Snapping while rotating with two locked rotation axis should snap to whole numbers

When rotating around one axis with R>Z snapping snaps to 5deg increments as expected.

When locking two rotational axis on the object (for example X and Y) rotation can also only occur around the last remaining free axis. Snapping however does not snap to whole numbers in this scenario. This is unexpected and should be changed in my oppinion.

This behaviour is probably a result of the rotation being dependent on the viewport camera direction when no axis are locked. Still unintuitive at least.