I've no idea if this is possible or not, but it would be so great. Instead of uploading more mod versions that fix some mistake you missed, you could simply press on your mod in "mods" section, do a fix in the code that comes up, and click "save". If players' textures can update automatically when changed, why can't mods?

I agree,
the mods with outdated versions of itself is just a waste of space.
Supported.

But then, what if a bunch of players prefer the original mod? There will be lots of complaints, because that original mod won't exist anymore.

Someone could just upload it with a different name.
If a large number of people played the mod at one point they're likely to have it in their mod folders, so it wouldn't get lost.

He's meaning more for when you upload a mod then think "shit, I forgot to do..." rather than retroactively prodding old mods into new ones

Well that's just too bad. If the modmaker wants to he can leave the old version be as is and upload new one with changes, but it should be up to the crator I think. If a maker of a popular mod abuses this power and pisses everyone off with constant changes people can just clone the mod and upload it themselves after all. But, as SkulFuk pointed out, I was mainly thinking of when you need to fix a mistake.

Yeah I don't think people appreciate that the mod makers to the absolute most popular mods aren't the type to just make major changes all the time. It could be the difference of just needing to change an engagedistance by 10.

Most obvious thing that comes to mind is how nearly every dueler turns off fracs on boxshu_mushu_v3

So yeah it makes sense to do it as Odlov is suggesting, which is why I support the idea.

The only problem I see is the addition of an "ownership" code to the mod maker and to that mod maker only, I don't know if that's possible

Maybe instead of doing all the code for it you could just simply create a sticky'ed thread for mod makes to list the old outdated versions of their mods and have them nominated to be deleted by staff members at their discretion. Just to help clean out the system you know. This way would be simple and keep the developers from having to do any code, plus it wouldn't have to be a regular thing, just check it every month or so kill off a few that are listed in the thread by the mod's creator. You could even pass it off as a Job to Trial GMs just to "test" their dedication to the job. Lmao, simple initiation jobs are always fun for Trials. <3