Hello Diablo fan friends. I'm looking for a mod that adds QoL and does not change the original way of playing. I tried a few that were suggested here but none worked with the GOG version.
Can anyone suggest one that really works without so much juggling?

I'd love that too!

Anything that changes appearance alone like HD textures and efffects but leave anything else original

Which ones have you tried? Also, DevilutionX is still in development, but once done that may give you what you are looking for.

I tried Torch, Devilution, DiabloPatch, nothing worked. DevilutionX don't work only on Linux?

DevilutionX is still in development. The author has posted here in these GOG Diablo forums and said that Devilution is just reverse engineering Diablo 1.09b so it gnerates an identical Diablo.exe, so is of little interest to end-users but is necessary for DevilutionX to exist, whilst DevilutionX is a project for modernizing Diablo 1, porting it to modern versions of Windows (almost there), Linux (done) and Mac OS (done, but not released yet). So it's not yet available but hopefully will be soon.
https://www.gog.com/forum/diablo/devilution_a_diablo_source_port/post3

There are two other ports that I'm aware of. Belzebub, which changes a number of aspects of the gameplay and so probably not what you want (there's also a multiplayer version in progress called Tchernobog), and Infernity, which seems to be very vanilla-like, but with some optional quality of life improvements as well as bug fixes.

Belzebub (The Diablo 1 HD Mod): https://mod.diablo.noktis.pl/download
Infernity: https://github.com/qndel/Infernity

Ooh Infernity seems just like what I was looking for in a mod. Thanks for sharing Korell!

Я так понимаю, вы хотели изменить визуальную составляющую и может облегчить какие-то действия.
Infernity вмешивается в игровой процесс

Can't make infernity work too. When I try to change the resolution the game crashes. The Hell 1 and 2 worked fine but isn't same Diablo gameplay at all. Has a lot of changes. It is a good mod, but not what Im looking for.

If you wan wait a week I think we will have solved the remaning issues in DevilutionX

the latest version of infernity available by default on github does not play nice with the gog dx wrapper
it implements some modfications to the rendering code which are stil in progress

I suggest you to try an older release (1.13 has no such modifications, if i remeber it correctly)
every released version is archived here
https://sergi4ua.pp.ua/mods/infernity/

Sure, Ill wait. I like what you doing. Thank you again!

I'm looking forward to this too. Belzebub is surely good but way too many changes for my taste and most of all the autoclick function is set too fast. Feels like cheating.

Any news about DevolutionX development? I followed the installation instructions but I still do not see QoL implementations. Is it still in the development stage?

Currently we are working on cleaning up more of the code (crucial for supporting more platforms and working with the next release of macOS in September).

Here's a list of improvements that have been done but not released yet:
- Per pixel transparency (this also allows multi layered transparency)
- Windowed mode can be set in diablo.ini
- Mouse capture can be set in diablo.ini
- Up-scaing quality can be set in diablo.ini (allowing you to set it to pixelated nearest neighbors)
- Included a font so that the credits and button text renders on all systems

There may soon also be a FreeBSD port soon

Keyboard and game controller navigation is also coming along nicely

We currently do not feel this is enough to warrant a new release, the goal is to finish some of the missing menu items first.