Reply by Loren

Oh I think it’s sturdy enough for planing but not long enough
and probably not heavy enough.

A lower stretcher might help a bit but imo it needs to be
either substantially weighted-down or substantially lengthened
to resist the forces of planing that lift the back of the bench
off the ground and mess up the cut.

Maybe I’m wrong though. I usually use a bench stop when
planing, not dogs.