I had the same thing with a rp23 HV shock on my Heckler, correct sag meant blowing through travel, add air to counteract this and it was very harsh over the chattery stuff. Seemed to be a no win either way.
Sent it off for a service to TF, which was due, and Push tune after lots of messing with different air pressure and set up, needless to say it made the world of difference. Still don’t really understand why Santa Cruz changed form a standard air can to a High Volume one, but hey ho.
You might get the same results from a Loco personal tune, but as I’ve not used him for this type of service I can’t comment (although the fork service he did was spot on)
HTH
Carl