Rotations 0° and 180° are working without issues. 90° and 270° are problematic because this not only depends on the general support of the hardware but also what format the buffer has. Apparently linear buffers don't work. What works are Y-tiled buffers. [1]
But for that to make work in general we need to support such buffer formats and allow graceful fallbacks from atomic commits on failed tests.
[1] https://github.com/swaywm/wlroots/issues/1058#issuecomment-459303758