Importing skeleton results in all bones facing a the same direction

[mattsteve]

I'm working with Bloodstained's psk models. When importing with default settings (except for "don't invert root bone" checked) modifying the mesh, and exporting, everything works fine in-game for only updating models.

However, if I want to replace animations, all of the bones are twisted in random directions (in-game). They look fine in Blender and in Unreal editor.

I suspect this is because the imported skeleton has all bones facing upwards, and with the same size.

If I check "Reorient Bones", the bones in Blender generally face in what seems to be the correct directions, but exporting to fbx and running in-game screws all the pre-existing animations up. Do you know what the correct setup would be for modifying a game model's animations in Blender?