I am sure that all Morrowind players would be aware of how to exploit the Alchemical Breakthrough, whether or not you actually (ab)use it.
Yesterday, as a deliberate experiment I decided to see just how badly Alchemy could be bent, and what is needed for Alchemy to actually break.

First step is the obvious one, gather your ingredients.
Second is to acquire your equipment. For this experiment, on PC, I was using the Secret Master equipment, made available via a mod.
Once I had everything, time to make the potions.

Start stats:
Level 57
Magika 204
Int 68
Luck 100
Alchemy: 100

Fortify Intelligence + Detect Animal potions
Ash Yams
Netch Leather
Bloat
Horker Tusk

Fortify Luck potions
Corkbulb Root
Guar Hide

or

Restore Health + Fortify Luck potions
Corkbulb Root
Corporus Weepings

DO NOT use
Guar Hide
Corporus Weepings
This combo will create Drain Fatigue + Fortify Luck potion.

You'll need ingredients for about 150 of each potion

Make the fort int potions in a batch of 5 and quaff, then make the fort luck in a batch of 5 and quaff.
Repeat these steps until either your Luck or Int stat is displayed in NEGATIVE values. This will be the warning that things are approaching broken point.
Keep repeating, and check the values for your creations.
Eventually, after having made and consumed about 135 of each potion, the created potions will start to break. Effect duration will begin to vanish from the secondary effects.
Keep repeating, and check the values for your creations.
After about another 10 of each potion, you'll notice that ALL effects have no duration.
When that happens, ALL potions created after that will have no duration. As a result, no matter how potent their effects value appears to be, they will have no effect because of no duration.

Finish stats:
Magika 1589592064
Int -901791744
Luck 1474803712

During the latter phases of the experiment both Int and Luck went negative, then back to positive, and Int finished in negative.

edit: fix miss-copied Magika start value

A few things:

First, before you make the first potion, create a spell with 8 instances of Fortify Alchemy 100 points for 1 second. This spell, which has a cost of 80, will drastically increase the power of any potions you make during that one second, and since you make potions while the game is paused, you can make as many potions as you want. In the later stages, this becomes less important, but if you have high Intelligence, you should have enough spell points, and high Luck will make your spells always succeed (both assuming neither stat is high enough to trigger integer overflow; see below).

Second, most negative effects can be avoided simply by having 100% Resist Magic at the time you drink the potion; this can be used to avoid that Drain Fatigue effect.

With those elementary facts out of the way, here is some more technical stuff:

Integer overflow: The game uses 32-bit signed integers to represent your attributes. This means that, if your attribute exceeds around 2 billion (the exact limit is 2^31 - 1 = 2,147,483,647), it will overflow and become negative. Normally this shouldn't happen, but since Alchemy lets you increase your attributes exponentially without limit, it is possible for your attributes to overflow, and that is what happened.

Of note, your Magicka is actually 3 times your Intelligence. It may not look it, but if you do the math and reduce the result mod 2 ^ 32 (to mimic the limits of 32-bit integers), you will get the correct result (note that it seems your Magicka is triple your Intelligence). Interestingly enough, your Magicka is not a multiple of 3 (it's congruent to 1 modulo 3).

If you are interested in this phenomenon, you might want to look up "two's complement".

No duration effects: This can be achieved easily without Alchemy; just create a magic item and leave the duration at its default value. Also, some effects actually work as 0 duration effects; Restore and Damage effects will change the stat by the magnitude instantly, as will Absorbint figured attribultes (Health, Fatigue, Magicka). Also, duration doesn't matter for some effects, like Cure Paralysis or Almsivi Intervention, so those effects will work normally. (One thing I am now curious about, but haven't tested; does a 0 second slowfall or levitate affect falling damage if cast right before you land?)

I just tested with Levitate (as my character doesn't have access to the Slowfall effect) and a Scroll of Icarian Flight. Without using the 0 second Levitate ring, my character (who has 64 health) died on landing; with the ring, I was able to reduce the damage to 6.

One thing: It seems that using a scroll will put you out of spell mode, so you will need to cast 'R' (under default controls) after equipping your item before you can use it. (This is something you need to worry about if you speedrun the game; to use a second scroll to survive the landing, you need to equip it, and then press 'R' to ready the second scroll.)

I was doing my experiment with straight skills, and not fortified ones.
The Magicka cost of the spell you referred to wouldn't be an issue. 204 Magicka, straight, so I could cast it twice, without fully depleting my Magicka. Thanks for those details.
I'd never known of them till now.
VERY useful to know.

The other thing not mentioned in your information, is another thing I saw, and didn't realise its import till now.
Magicka is unaffected by the +/- sign on your INT. Magicka ALWAYS stays positive.

edit: fix typo

Fortifying your attributes, particularly Luck, can have similar effects to fortifiying skills. In particular, the examples I gave in another thread regarding Mercantile and Speechcraft can be reproduced by having enough Luck.

The use of Fortify Alchemy is to speed up the initial use of Alchemy; using that spell for the first batch of potions will save you time by letting you start with stronger potions. Did you ever have at least 2,147,483,648 (=2^32) Magicka? If so, the game uses an unsigned integer or a float. I am wondering what happens if you save and reload with that much Magicka; is it saved properly?

I have been able to get negative Magicka by having a Fortify Magicka effect wear off. This negative amount is not displayed, but Restore Magicka effects won't have an observable effect until they restore enough Magicka to make the total positive again. On the other hand, saving and reloading would reset the Magicka total to 0.

I gave your idea a go, and reached negative Luck in about half the time it took with my first serious attempt at testing. However, it happened too fast for Int to reach negative. In all my records from testing, so far, no.
Highest I've seen Magicka reach was during today's testing.
I didn't try to save at that point. I should have. :( These are the figures from today's testing:

At 10 cycles of 5 potions each of Fortify Int and Fortify Luck created and consumed:
Int: 601,122,608
Luck: 1,102,252,416
Magicka: 1,803,685,888

55 Fortify Int, 53 Fortify Luck
Int: 2,020,803,584
Luck: -1,631,182,336
Magicka: 1,767,443,456

55 of each
Int: 2,020,803,584
Luck: -590,160,896
Magicka: 1,767,443,456

These are the end state 0 duration potions:
Fortify Int + Detect Animal
Fortify Int 954,269,903 points
Detect Animal 1,272,359,823 ft

Fortify Luck
Fortify Luck 954,269,903 points

Thinking about what you said about the Fortify Alchemy spell, gives me an idea for a further experiment.
A ...minor... piece of God Modding.

1. CE enchantment on self, 8x200 Fortify Alchemy
2. Amulet, 2 rings, belt, shoes, pants, shirt, l+r gloves, robe, greaves, cuirass, l+r pauldrons, helm, shield. ALL enchanted with that CE enchantment.
3. Alchemical equipment, 500 quality. To give a sense of scale, the inaccessible Secret Master equipment is merely 2 quality.

I'll report back, in a new post, with the outcome of this testing.

So much for that idea.
I think I overdid it.

Stats before making or taking any potions:
Int: 68
Magicka: 204
Luck: 100
Alchemy: 25700 (16 items of clothing/armor, each with 8x200 Fortify Alchemy, on top of my base stat of 100 Alchemy)

First potions:
Fortify Int + Detect Animal
Fortify Int 4287634 points for 1285990 seconds
Detect Animal 5716345 ft for 17146034 seconds

Fortify Luck
Fortify Luck 4287634 points for 1285990 seconds

After taking 1 of each
Int: 4287702
Luck: 4287734
Magicka: 12863106

After taking 5 of each
Int: 21438238
Luck: 21438270
Magicka: 64314712

This pushed things straight to the 0 duration point.
The second set of potions were:
Fortify Int + Detect Animal
Fortify Int 718893340 points
Detect Animal 958523996 ft

Fortify Luck
Fortify Luck 718893340 points

I decided to test one more thing:

My character has 3x Int as Magicka, so I decided to set her Intellgience to 800,000,000 using the console. The result was as follows:

On the status screen, maximum Magicka appears as -1894967296, but if I move the cursor to the Magica bar, the unsigned value (2.4 billion) is shown.

At not so full Magicka, the magic meter on the bottom of the screen is empty, but spells can still be cast.

At full Magicka, the meter is full, and the status screen gives spells a non-zero success rate, but if I actually try casting a spell, I get the "not enough Magicka" message.

I even tried using the greater power Berserk (which costs nothing and always succeeds, but can only be used once per day) and I *still* got the "not enough Magicka" message. (I actually found this behavior in Oblivion as well; negative Magicka prevents the use of 0 Magicka cost greater powers.) Guess you still need to have enough Magicka to cast a spell, even if the cost is 0.

(Items still worked fine.)