I have an AR on the way but have never used one (yet).
I can however help with the PC latency thing if you’re using Ableton Live and have Max for Live.
In the most basic sense of how it does what you need: It sends the program change message as soon as you arm your next clip rather than at the start of the clip playing.
Right now I have it set up to only work with Overbridge (sending note changes on channel 16).
Version 0.3 will have the option to use MIDI program changes (without Overbridge).
Version 0.3 has really mostly been done for a while but I haven’t taken the time yet to finish it up for release (soon).