A little bit. A lot of times people will get animation packs or skinned meshes from the Unreal Marketplace which are designed to work with the default Mannequin bind pose. If this rig generates animation with the orientation offsets, there will be some unexpected deformation changes. If we generate and import the Unreal skeletal mesh from the mGear skeleton, it would mean most animation from the marketplace would need to be retargeted and skeletal meshes would need to be exported and reskinned at this bind pose.
I tried adjusting some of the guide rotations but that didn’t seem to effect the joint orientation much.
There are some workarounds if it would be too hard to match orientations such as constraining a deformation skeleton to the mGear skeleton.