I was looking for information on how to change the slider border transparency, and I only found old threads and a post on reddit where it was said that it can't be done, and I even found a feature request about it, but all of this is pretty old - has nothing changed since then?

No

Redo_ wrote: 3eig

No

thanks

I should probably explain

Stable is feature locked. No new features will be added.

Only chance for something like this would be in lazer. But I'm not aware of it being planned. Not only is skinning in lazer super barebones, it isn't even the primary focus of development, and probably won't be for quite a long while.

If you (and other) think this feature should be a thing, you should bring it up in the discussions on GitHub. Make sure to adhere to the pinned rules.

Redo_ wrote: 3eig

I should probably explain

Stable is feature locked. No new features will be added.

Yeah I know that, I mainly use lazer so I itted the possibility that this could have been added already, but no big deal, it's clearly not the #1 priority right now, there are many more important things to do for devs.