bold hatch
I personally hop around between versions a lot, and a version switcher on the homepage would be a super awesome and unique mod to have. I've attached an image of where it could go, maybe as a slider between different versions or just buttons to change. It would reload the whole game onto the new version, without having to fully restart Lunar. Something similar to Jello Portal from Sigma Client (if anyone remembers that client), which had a feature similar to this.
elfin blade
it kind of has to reload the entire program for things to work smoothly
and otherwise you would need a lot longer initial load times just so that switching versions is seamless(ish)
in my experience its not that hard to just close the application, open the main lunar menu, select your version, and launch
all this would do is make it so that you need like 3 or 4 less clicks
unless you want the game to not even close and reopen, and instead just switch to a new version within the same application
in which case, again, way too long initial load time
echo slate
maybe, you could make a feature where you can join servers with multiple versions but it doesn't affect singleplayer?
limber wing
It would too much bulk on lunar client, which is against their smooth and clean asthetics