Is it possible to dump a "built in" device from a JP1 remote with IR or RMIR?
The reason being to see what is all implemented and secondly to be able to then load it as a device upgrade into another remote that doesn't have it as a built in device.
No, it isn't possible to dump a built-in device using IR or RMIR. However, the Lookup Tool (link at top of this page) gives EFCs for many built-in setup codes. You'll probably find what you need there.