i do not think finding excuses for ue works here, i understand very well an engines limitations but this is not one of them. Proof unity works and i would bet you cryengine may work just as well.
also scaling a rig is not an option especially if your rig is anything decently complex for proper custom character animation. Also building scaling functions in the rig is a large task of its own and not recommended for most cases. I know because i have been rigging for 15 years. If a rig can be scaled in blender then it is either relatively a simple rig or a stock rig used for multiple purposes similar to CAT in max but start adding more functions and no.
the only way to scale it in that case is to scale the fbx export rig itself which i am already doing as a workaround.
lastly i disagree completely of unity being an inferior graphic engine its slowly proving to be the contrary just wait and mark my words when in a few years unity develops their visual scripting how indie devs will start flocking there. If you think it slows down something else in the engine then i believe the best judge of that is the dev not the engine, the engine should provide the options and we choose the compromise.
this is a problem in ue, again sorry no excuses i am raising it here becuase it is and causes headaches. If Epic cares fine if they dont we have to live with it and i dont have the resources to dig its core looking for solutions and most other indies don’t either.