Unity Import converts units sometimes in meters sometimes in cm

I’ve noticed on importing fbx models Unity offers one of two conversions:

1m (file) to 1m (Unity)
or
1cm (file) to 0.01m (unity).

Does anyone know what causes Unity to offer the one or the other? (I’m always exporting from blender 2.82 with the same scale settings). It feels like converting 1cm to 1cm would be the same as converting 1m to 1m, so it shouldn’t matter which option you are presented with, but I’ve found I cannot correctly combine clothing imported with 1cm to 0.01m with a model imported with 1m to 1m, so I need a way to make Unity offer the same conversion on both geometries (using skinned meshes by the way)

Seems dependent on selection of: blender::fbx export > transform > apply scalings [FBX Units Scale]