Hey, thanks for the comment. Having a sclae value is definitely a good idea - I'll put that into the next update!
Regarding the beta version of magicavoxel, it adds in some changes to the vox file format to support animations and per-frame objects. If you're using them features then it's doubtful they will work.
However if you haven't used these features, then the program should still work. I'll have to look into it and run some tests before the next minor update to see why it's saying things aren't compatible.