Thank you sir for both helping resolve this and improving my knowledge concerning on whose court the generation of offline installers lay :). I will no longer bother devs with this particular issue and will go straight to gog in the future ;).

Ok, save game for exophobia solved for offline installer.

That's reassuring! Thank you for your in-depth replies about this topic!

Don't be so sure about Thief 3 GOG version,I have it installed & found this in my registry the other day while I was doing a clean up of old entries from other games.

Was going to contact support once I finish the game if I can't delete it from the registry without the SecuROM removal tool.

Those are just passive text error messages that can be (but aren't) called by the DRM that's no longer there. The disc version originally had SecuROM 5, however if you install the official editor the original SecuROM'd .exe gets overwritten with an v1.1 executable with no DRM. "Sneaky Upgrade" does the same thing. GOG has pre-patched their version in the same way. Game runs fine with Process Monitor (the thing that triggers FEAR) running. The only registry entries actually required by the game are:-

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Ion Storm\Thief - Deadly Shadows]
"path"="C:\\Games\\Thief 3"
"ION_ROOT"="C:\\Games\\Thief 3"
"SaveGamePath"="C:\\Games\\Thief 3\\SAVES"

Everything else like the \SecuROM sub-keys are extraneous leftovers. If you zipped the game folder up, unzipped it on another PC and added above entries (correcting for location), it should work fine. In fact I don't even have the \SecuROM and \Locale keys on mine. Try backing those keys up and deleting \SecuROM and the game should run fine. It's just another example of how the registry is absolutely plagued with clutter.

Thank you for the good news!

In addition to the information already present here, the following information applies for Baldur's Gate 3, according to another person:

as for "Baldur's Gate 3": mod manager is merged with game now, so you can install modifications directly from main menu (works also on "cracked version"), but you must have "Larian Studios account", otherwise you have limited access to modifications database IIUC. its another form of DRM, i guess. thought you can still download/install modifications manually

I don't know if they've already been mentioned, but Spore uses a web connection to Sporepedia (legacy service run by EA/Maxis) for significant amounts of user-generated creatures, vehicles, missions, buildings, etc. There exists Spore Creation Zip Porter on Github, a mod that allows you to archive Sporepedia content for offline use. The GOG version of Spore also does not include the problematic Dr. Pepper promotional robot parts DLC (though these, too, are easily installed and fixed from a mod).

Mortal Shell had Twitch drops, which required connecting to promotional streamers on Twitch during the game's release period for ingame cosmetic skins; I helped archive that "DLC" and have since put it on PCGamingWiki. It is no longer available by any official means; you must edit your savedata.

I had a whole bunch of links for sources for my info in this post, but my account can't post links for some reason.

Low rep is the usual cause, since it might have been hidden from view, but the system still exists. You can check it in your forum settings.
The workaround is to include them in quote tags.

See here:
https://www.gog.com/forum/general/games_that_treat_gog_customers_as_second_class_citizens_v2/post4546
and following posts.

Latest (last) update of Dead Cells GOG version broke the ability to play the Daily Challenge. 3 items in the game are locked behind that. I'm going to submit a bug report to the developer.

Modding can circumvent. Ideally, since the game is now "complete", they'd rejigger how they unlock in general.

https://deadcells.wiki.gg/wiki/Daily_Challenge#Rewards

https://www.gog.com/forum/dead_cells/daily_challenge_wont_launch_1

OK. To the list it goes.
.

Thank you! Keep us updated how the bug report goes!

Was my post about Baldur's Gate 3 ignored?

I think Bethesda games like The Elder Scrolls III: Morrowind, The Elder Scrolls IV: Oblivion, The Elder Scrolls V: Skyrim (both editions) and maybe others, while not having DRM themselves, still deserve a dishonorable mention. They have a lot of bugs, and require some mods (Unofficial Patches at least) to be installed to make them playable without being afraid to accidentally trigger some game-breaking bug which only gets noticed much later (at least it is so in Oblivion, but the other games mentioned have Unofficial Patches for them too). And installing mods is a big annoyance, when the websites where they are hosted (mainly Nexus Mods) often require registration and try to convince people to pay additional money for premium features.

Bugs as such aren't DRM. They become DRM-like if GOG and the dev decide to fix them for the Galaxy or other ownership-verified version but not for offline versions. But as long as the bugs affect all versions in the same way, they are just sloppy programming and poor customer service, not DRM.

As for the mods, for me the essential sentence is what you wrote here: So I don't really understand where the problem is. I have nothing against an optional mod-manager, as long as it's use isn't enforced. The entire idea of the offline installers is, that you can install them manually without resorting to a client and without proof of ownership. The same is true for mods. If someone wants to use a mod manager that needs some login data, that's their choice. As long as I can download the mods manually and install them on an offline PC, I'm content.

If there is game content that is only available through a client-like software with login requirement, then yes, that content is DRMed. So if there's a misunderstanding and if there are mods that are only available by loging in to the Larian Studios Account, then BG3 requires a mention in the list. But as long as your last sentence is true, then I don't think that it needs a dishonorable mention.

Only if those would be official mods. Anything unofficial / user-created is not actually part of the game and has nothing to do with the devs, publishers or store.