I am creating a library mod for 1.21 which would use LibMultiPart, if it is updated

Ok, I've published 0.13.0-pre.1. I have not tested it yet, but I plan on porting SimplePipes shortly, which will allow me to make sure LMP works correctly.

Out of curiosity, what's the library that you're working on that uses LMP?

I've been putting this off lol. I should be able to have LMP updated within a week, if not sooner.