I believe that you cannot customize / edit what PC changes the H90 sends or send them without changing the program on the h90.
In other words the H90 sends the same program as it sees internally (changing from program 10 to 11 will send PC11 to the other devices). This may not be an issue with your set up but I couldn’t quite organize my thoughts to get it to work with mine, as I sometimes want to control one of the other midi pedals without changing the program on the H90. (I did downsize from a MC6 to a disaster area dmc micro pro however, as the H90 did most/all of the performance stuff I’d used the MC6 for).
ideally, a future version would allow you to assign PC or CC # to hotswitches or other (external?) switches on the H90.