A really great feature for PS for iPad would be the option to activate the Apple Pencil hover feature to preview what your brush tip looks like before touching the screen, sadly this feature would only work on 4th gen and onwards iPad Pro models or so I believe but still it would be extremely useful (I personally feel I lose precision if I can't see what my brush tip would look like before adding a stroke).
Also the ability to modify the smudge brush and give it custom shapes and properties like those found on the desktop version would facilitate blending for artists that created a specific brush for it.
Thanks for hearing out my suggestions! Here's hoping they get picked up!