Transmit MIDI Pitch Bend and Aftertouch
Title says it all really - the ability to sequence pitch bend and channel pressure/aftertouch as we can with other CCs.
I can't be the only one who uses pitch bend a hell of a lot. Pitch bend and aftertouch are also 'hard wired' to key functionality on certain hardware (e.g. Sherman FIlterbank) and are often supported on devices that only support a narrow range of MIDI control parameters (e.g. DSI Tempest).
If there's a problem storing the higher bit depth values per step then I don't really see an issue with having 'bit reduced' versions - at least we can then use them!
Personally I don't see a pressing need for polyphonic aftertouch but others may disagree.