System Information
Operating system: Linux Mint 20.3
Graphics card: GTX 1660

Blender Version
Broken: 3.1
Worked: (unknown)

Short description of error
When exporting an FBX to Unity, with "Apply Transform (experimental)" checked, the scale of meshes is accurately exported; however, animated armatures remain at a scale of 100.

Exact steps for others to reproduce the error
Simply export a mesh, and its associated armature, to FBX with "Apply Transforms" checked, and open in Unity (or presumably any other FBX-compatible software). The mesh itself will be the correct size, and all transforms of the armature bones will work; but the armature itself will be scaled to 100. This is a problem down the production line, as any modular attachment to these bones must be scaled down by a hundred, or the result will be enormous meshes breaking the scene. This can be worked around, but not effectively corrected after the fact, to my knowledge.

To be complete, my selections on the "Export FBX" dialog include "Selected Objects" (with the mesh and armature selected), Z Forward, Apply Transform, Apply Modifiers, and Bake Animation (though there is no animation to speak of, this was the default). I have deselected "Include Leaf Bones".

The objects selected are titled "Carriage Frame" and "Frame.Mobile.00.Armature". I recognize that "Apply Transform" is experimental, but this would go a long way toward bringing it out of that phase. Thank you for your attention!