I’m 80% sure that SPR builds can only resist magical CCs and not physical CCs.
Example of Magical CC:
Frozen
Raise
Example of physical CC:
Stun
Root(full draw)
All Hunter skills
Knockdown
Pain Barrier should probably ignore Hunter Skills. That would be a pretty reasonable and sensible nerf.
I say this as a player with a Hunter3>Falconer2 that I both love and hate like most Hunters.