Shared memory clients currently send wl_surface.damage events, which are warned against in the wayland protocol:

Note! New clients should not use this request. Instead damage can be
posted with wl_surface.damage_buffer which uses buffer coordinates
instead of surface coordinates.

So although technically still supported, support for this request may become spotty in the future, and some compositors may start falling back to non-partial updates in order to simplify their code and circumvent scaling issues with wp_viewporter and buffer scale.

We should start using the new API if the compositor has wl_compositor 4 or newer.