AFAICT, the only piezo-equipped PRS model in Core with Pattern Thin Neck is the P24, and it has a trem. Not even an option for Pattern Thin in AP for the P22 (Stoptail) or HBs, P245, etc.
However, there may be Wood Library or other Dealer-specific runs that have the combo you want, or scour used (or NOS) models.
The limitation of neck carves on the models, even AP (which by definition is special order, not off the rack) is quite baffling to me.
I didn't do an exhaustive check: perhaps only 24-fret necks are available in Pattern Thin, and PRS simply doesn't want to bother with that neck carve on any 22 fretter?
EDIT: well, not the case. You can order a 408 (22 fretter) with Pattern Thin neck.
Bizarre.