After much research I was able to modify my PA52 upload template to work on v9 - posting this here in case it helps anyone else. My template now reflects the following:
(H),_f0,TC
_f52,PCT-COMPANY
_f55,PCT-EMPLOYEE
_f58,PCT-ACTION-CODE
_f62,PCT-EFFECT-DATE
(H),_f63,PCT-ACTION-NBR-K (I added this per KB 1199678)
_f66, PCT-REASON11
_f74,IMMEDIATE-ACTION
_f77,PCT-UPDATE-BENEFIT
_f79,PCT-UPD-ABS-MGMT
_f81,PCT-UPDATE-REQ-DED
(H),_f14,PAT-FLD-NBR-111 (I added this per KB 1204713 - it holds the value "62" which is the Rate of Pay field number)
_f107:0,PCT-NEW-VALUE-11
_f350,_HK (A concatenation of Company - ours is four digits so 5 zeroes added, EE Number, Reason, Date, and Action, Nbr with 3 leading zero's - e.g. 1000000001234PAY CHANGE201607030001)
(H),_f9,ORIG-COMPANY
(H),_f10,ORIG-EMPLOYEE
(H),_f11,ORIG-ACTION-CODE
(H),_f12,ORIG-EFFECT-DATE
It's always an interesting process when a template that has worked for years suddenly no longer works, but I'm happy to report that it is working beautifully now! 