if i was you i should use, this is because if you animate a rigged mesh you cant separate the fingers from the hand itself with seperate meshes it looks goofy
Or using a rig for the hand, and manipulating the finger bones to look good.
You can make an armature in blender for any model and it will properly import, you can animate inside roblox and make poses. It’s a pretty painless process, just look up how to make armatures and they should import as expected