I hate it when game saves at the end of turn. If something goes wrong, how will I be able to change anything? For example, plenty of times I stopped at the wrong place with no movements left and I got ambushed by the party, which simply oneshotes me. Sometimes i managed to drive it away by wasting all elixirs and thus scaring the enemy, sometimes I managed to block passage by summoning a creature. When playing as dwarves, I can use spells for extra movement. But everytime it felt like "Thanks god I had suitable scroll/any elixir/suitable spell/enough mana". And if I dont have any of that? I will be left with undeniable fact that I am going to replay the entire mission or half of that because of... what? Broken mechanics? I dont save manualy that much - mostly before important events like when i`m ready to go for the capital. Its too routine to save manually every turn.

By now I`ve completed both main campaign and add-on with 3 races (except for Legion of the Damned) and I`m tired of dead-ends like mentioned above.

Because of what?
Console casuals on PC at them finest. Asking for auto-saves cause they dont saves game manually and at same time asking for no-auto-saves. Broken mechanics, yep.
Or you just hate every PC games even if they work same as usual for you. Because you are a bad player. Sarcasm: of course this is game fault that you bring yourself to dead-end point!

Routine to use [Q]-uicksave?

While I may agree that a 'begin of turn' autosave would probably be a better option than the 'end of turn' autosave, it's always meant as an extra layer of protection, not the main save system you should rely on, hence nothing is "broken".

There is an happy medium between manually saving at every turn and manually saving only an hour+ before, so that is kind of your fault... especially since you just said you completed multiple campaigns, by now you should have learned the lesson

Are you really talking to me or is it just some painful flashbacks that cloud your vision? I`m not console gamer and never was

Protection of what sort? If game breaks during AI turn, that kind of things? If yes, then ok, I`ll take it as working just fine, simply not as I thought it would.
To be honest, never thought from that perspective before.For me autosaves always have been like main saves (due to them being every turn) and manual save always have been additional saving mechanism in case something really big is going to happen.
During my last campagin I really did save more often, but still I considered this additional. Well, you`ve opened my eyes.

Well, simply protection from the user forgetting to save on their own, so you have at least one option to not completely restart the whole level.

In turn based strategy games like these (HoMM series for example has the same type of autosave), it's not rare to realize only after a while that some bad decisions has been made way earlier in the mission, hence keeping a regular set of manual saves every, I don't know, 10 or so turns is never a bad idea.... going back just one turn, even if it was the start of it, may not be enough

The end of turn autosave on the other hand should be used mostly to just fix minor mistakes quickly, like not moving a unit in the right spot, or retrying a battle differently and such...

A start-of-turn autosave would be worse, since it would save that your main hero got killed (from the ambush on the AI turn) before giving you a chance to reload.

Some newer games keep autosaves from multiple turns to reduce the need for manual saves, but unfortunately there is no such luxury here.

Not if it's implemented correctly: game saves at the start of *this* turn in a temporary file, and then, only after you push the end turn button, it moves the savefile into the actual autosave slot

So from turn 2 onward, you now always have available a save from the beginning of the *previous* turn

Yes, it works if the game keeps the last two autosaves. But I guess we're in wishful thinking territory now, at least for the Disciples games.