Thinking of converting a ton of songs (and maybe some obscure IRL ones with an extremely low to zero chance of getting copyright blammed) from my personal VGM playlist to OGG for use in NeoLemmix. Is there already something like that or would anyone be interested?
Don't think any such thing already exists.
If you mean ones in actual VGM format, look up a program called BRTSM Convertor. It can convert to a format it calls "Looping Ogg", which has a LOGG extension. This is actually just OGG with some extra metadata tags that tell it how to loop - and NeoLemmix understands these tags. :) (You will have to change the extension back to OGG, though.)