If you mean:
1."once you download you don't have to redownload so 'it's not a problem'".
No. Actually that's the whole point. My point was about the fact that you have to go to a website outside of control of company selling game to obtain the patch.
There is countless ways this could go wrong, ranging from the website getting hacked and patch being replaced with malicious one (not unreasonable, definitely not that uncommon) through things such as "maintanance" as well as "domain holder forgot to renew the domain, someone used the time to obtain it thus the address changed but many people did not find the new one so they got locked out" all the way to "natural disaster happened / a-bunch-of-raging-anti-hentais-raided-server-room-and-physically-destroyed-servers and we subsequently lost possibility to host it".
The point is, the website is totally independent from GOG and thus is outside of jurisdiction of GOG.
Also, what about versioning, what if the patch would be updated and only the latest version would be hosted publicly?
What then? You would effectively be artificially forced to run the most recent version of the game to use the patch.

Not EVERYBODY has to buy the game TODAY and download the patch TODAY.
The website could stop hosting the file at any moment. Even human error (such as refactoring website and forgetting to fix broken link) could result in it.
My point is, IF the file would someday stop being hosted, say in few years, then there would no longer be any official source for it (assuming there wouldn't be a new one made) and at that point good luck obtaining the patch "from unofficial sources" while being 100% certain that it wasn't tampered with.

2.If you mean "it should just be an extra or free DLC offline installer on GOG".
Well yes. "Too bad the company in question (GOG) doesn't seem to care".

My entire point isn't about storage, which would be needed for base game anyway, just about OBTAINMENT.
Yes, theoretically it's not a problem to back it up. BUT that assumes you actually managed to obtain it.
And indie game websites aren't going to be live forever, even official ones.
In 10-15 years the patch may no longer be live.
Anybody who did not obtain it in that time would have to obtain if from "unofficial sources" with no guarantee it's vanilla untouched file.

With which he entirely missed my point.

I mean... If you feel confident enough that some random on the internet "totally has the original unmodified file" based just on said random's words...
I don't see checksums on the official website. So, you know, until they show up you have NO idea if the file you are downloading from "unofficial source" is indeed unmodified.

PSA:
So for preservation sake to at least somewhat alleviate my above desribed issues I went ahead and saved the file in webarchive :D
https://web.archive.org/web/20210208230523/https://www.huniepop.com/patch/HP2SteamyPatch.dat
(before someone tries to turn my own words against me: go ahead and check that the link for the patch from official faq site links to exactly " https://www.huniepop.com/patch/HP2SteamyPatch.dat " and I saved in archive org exactly that)

EDIT:
GOG for whatever reason cuts everything before the last https in links (that or deliberately criples archive org links) so you have to manually copy paste the archive org link as otherwise by merely clicking on it GOG forum software will strip everything before last https and guide you directly to live site instead of backup

Right. Regional locking sucks. In that case, a bit of (avoidable) censoring and 8 cents don't really matter.

No, it is becuase adult games are hidden on Steam, unless you allow it to be shown. AFAIk you can also put on family filters. gOg, on the other hand, has no gateing for content.

There are quite a few games on Steam now which are very adult. such as the Madmind studio games (Agony Unrated and Succubus), Movie Games next game (Lust from beyond), Acting Leassons, Being a DIK and many more. As long as you now go behind the 'Adult Only' curtain on Steam, you can find many.... interesing?.... things.

Edit - to see if your Steam account allows adult content, try this link: https://store.steampowered.com/app/985830/Succubus/

Since when are things blocked in Germany for sexual content (the game is marked as adult only)? Are there any new laws? Usually blocking is enforced for violence only.

Yeah, afaik by default the "adult only" tagged titles are filtered off.
All these ACTUAL porn (not to be confused with hentai) games aren't "in your face all over the store" by default which makes me cringe when "some" people in this thread say their "entire Steam pages are filled with porn" - I mean, lol - it's entirely responsibility of such person to set the settings to not default and let that happen :P

I don't know how it is in this game, but the first one it was just pictures of women in positions (which didn't show any character other than the woman). The Witcher 3 actually haad sex, with movement.

Could someone who has a friend who bought this game kindly answer this question about Polly? Obviously some people will see this question more important than others.

Except I didn't (forget that point).
My point was precisely that GOG as a distribution platform has arguably better durability of their server infrastructure and it's harder to bring down GOG than some small external website sitting on Apache server hosted by some obscure corpo hosting a bunch of small-traffic sites and with domain name set to expire in around 4 months ( https://www.wmtips.com/tools/info/huniepot.com ).
Probably even casual distributed denial of service would bring this website down whereas GOG could MAYBE survive longer (I say maybe because I have seen GOG services go to sh*t in the past during giveaways but that indicates more of infrastructure not being ready for load and not neccesarily actual DoS protections).

If it would be in extras you would still be able to access it if the game store page would be brought down.
And if it would be free DLC - well - as long as you obtained the DLC before all that got brought down you would still be able to access it's installer.

If there are official GOG posts linking to modding sites then GOG is stepping on paper thin ice.
What digital distribution company would in their right mind link to website ENTIRELY outside of their control that may host ANYTHING, INCLUDING illegal, distasteful and malicious content?
Such behaviour is nuts and should not be seen as "this is fine" denominator in regards to relying on external websites to host what effectively should be present in game's extras.

EDIT:
you know what I just realized my mistake (thanks to two different things (????) being hosted on same address depending if www is present or not and since nosrcipt strips it in "check this domain" I got different result first - which normally wouldn't be a problem [because normally only one website is on the address regardless if www is present or not, most domain owners are sane enough to ensure that] - but I guess in this case it's a bit of wtf moment).
The website server obviously is not exactly on Apache.
So here is my correction. Gomenasai.
But my point on obscure corpo and low-traffic (thus likely not much DDoS protections) remains.

But when you cannot buy the game anymore on GOG there would be no need at all to get the patch. ;)

If you already would have bought the game the patch still would be in your account, available together with the game, as it should be. If not, there again would be no need for the patch.

That's something different. This is an official patch which for me is a part of the game. Mods are external add-ons and not part of the original game.

Because there's sexual content and then there's SEXUAL content.
Meaning that showing bare breasts/nipples and primary sexual characteristics (male and female, during full frontal nudity for instance) is still A-OK (in Germany at least), but when it comes to erect peckers, spread vages, insertion of objects or actual penetration on display it would generally count as pornography (not just in Germany but everywhere else as well) and as such would need to be rated differently.

Where do you stand on DLC?

I can't believe they would CENSOR THIS ART anyway does anyone know if there's anywhere else on the internet where i can see boobies please help

I wonder as well why this is blocked in Germany? There's never been a problem with sexual content in games here and as far as I know there hadn't been any new laws. Can also still buy all other erotic games on Steam and other shops. So blocking this one doesn't make a lot of sense and I doubt it is really neccessary.

Some of the still images (in their original uncensored form) you're rewarded with likely depict spreading of the vages (dripping with bodily fluids) or inserting of digits/objects into other cavities as well, which should count as pornography, even in Germany.

That's usually rated P16 in Germany, at least for movies.

As far as I understand it that's what rating P18 in Germany is for (which fits as the game has a P18 rating according to GOG's game card) and usually not a reason for being illegal or completely banned.

But I'm not an expert and just was curious if something has changed in German laws lately which I've missed.

Are such games also blocked in Germany? Or only Hunipop 2?

So apparently other games I also would classify as porn are not blocked and for me it still isn't clear why Hunipop 2 is blocked. Perhaps blocking it might indeed not be necessary.