Sorry for the delayed reponse. 
re: VATs.
I have not used VATs myself yet, partly because blending does nt work (so easy) anymore and it is a rather big change in my assets workflow. But I know that @oriongu did some pioneering work over here (just browse the thread backwards).
Can you load the character models without animations? I think this would be an important performance test and the safest thing to answer the question (more reliable than stats I mean).
One last thing: as far as I could read, the number of bones is what slows down animations. If by chance you use Mixamo animations, notice that half of the bone count is due to the fingers! If you do not need detailed finger movement, best case would be to just delete the finger bones in Blender (or whatever you use). I would hope that this gets a big performance boost. I have not tried this but it sounds like less work than using VATs.