Also with a lot of radio amateur use there will be a single antenna, with TX and RX on the same frequency and the need for PTT switching. I believe that a popular API for apps with this on Windows is ExtIO.
Sounds like we need to schedule the work required to support both these use cases, plus perhaps other non-TX/RX switching uses. Given there are multiple GPIOs, some could be used for switching in/out external filters and amplifiers etc. also. So some simple mechanism for just toggling GPIOs would be nice.