This isn't an answer, but more of an observation for 3.2 stable.
I found that FBX mangles my mesh, and therefore the animations look horrible. I abandoned it after many attempts to make it work.
I found that glb works the best between Blender and Godot, but Godot has terrible design-time support for importing glb. It's so painful that I find it easier to export my animation as separate obj frames, and then animate them manually. It takes a TON of disk space, but the results are easier to maintain. But once the glb is actually imported into Godot, it works well.