PICPgm's home page lists a bunch of devices that it's explicitly compatible with, but my relatively new one isn't in that list. There's a way to add a new programmer by editing a config file, but adding a new device is glaringly absent from any documentation that I can find. PICPgm's forum is 404, and Microchip's forum isn't very helpful either.
Microchip's Programming Specification for my device suggests that the hardware is okay, in that the Pi's GPIO pins are capable of providing and accepting the right signals for Low-Voltage-Programming (LVP). So before I dive into this ratsnest of hardware again and bury another new module into it, how can I be sure that I won't have to dig it back out again just to put my PICkit on it?
(I'll just leave the programming interface permanently connected to the GPIO's, which are normally configured to let the chip run.)