Well..yes that works of course and that's what I've been doing. But I dread that day when new feature in newer version A:M (eg texturing, surface properties) gets wiped out by going back to older version (not always able to go backwards and retain new data).
I tend to do my weighting, texturing, surface defs, materials, etc on the pre-rigged character. So the choice is to do all that in 16b (and not have new features available) or to do that in later versions and have it wiped out when go backwards.
I don't think there's a case like that yet, but if there were and you still wanted to go back to v16 just for TSM2 I think you could use a text editor to swap v16 bones and constraints into the model file from the later version.