When left handedness is set as a skin customization option in client settings, the block breaking particle effects (block textured particles coming from what's being mined) soak into the right hand instead of the left hand.

The gun and beam emit from the left hand just fine, but the particles do not. I checked with another player on the server and the handedness is correct, but the laser AND particle effects are emitting from the right hand instead. When handedness is set to right, it all appears correctly.

This was apparently fixed in two separate issues: #32 #52

What minecraft and mod version is this?

1.20.1 Java edition, running AllTheMods9, version 0.2.6

Thanks, I'll check it out

What minecraft and mod version is this?

Should be fixed in the next version :)