Incredibly minor, but I thought I'd point it out anyway. I'm not sure if this is even a valid issue given that the jar I'm using is for 1.19.3 (although it seems to function completely fine otherwise).

They'll need to be incremented by one more pack version in 1.20 as well.

The jar file that says on the website that it's for 1.19.4 is actually for 1.19.3 but works fine in 1.19.4, so yes it is minor but, once they update it, they need to change the pack version.

As the latest version is no longer 1.19.4, is this still valid?

This was fixed in beta 3 but I forgot to close this.