is it okay to wait for a 1.21.4 version?
is it a major effort for the developer? thank you.

I'm currently running a poll in my Discord to see how large the playerbase is.

We'd have to abandon it almost immediately if we were to create support for this version, that's the main thing holding me back. 3 version support is already a large amount, and actively maintaining a fourth for a version that potentially very little people play (now that it's two versions behind) is ultimately a bit of a waste of time.

The answer is this won't happen. The demand seems too small for this, and I just would rather not bother.