Is it possible to use two blend spaces at a time?

one for some bones and one for some others (in details, arms/fingers and chest legs).
i’m trying to find a way to override the upper body animations, but apparently there is no support for partial bones animations in UE, nor any way to do it, other than setting bones locations manually.

You should probably check out my answer here:

Yeah it is. Use “Layer Blend per B”.