We originally had it spec'ed to make simple elements be valid payloads. That descended into discussions about the many possible ways R0 could get expressed (string with one or more formatting options or raw with all the variants of bytes ordering...it gets complicated fast) and we decided to leave it as a simple string buffer for now. You can use STRPRINT or STRPUTB to stuff anything into that string buffer, so you can build whatever payload you want. Yes, it is two steps, but it is also infinitely flexible. We would still like to allow you to stuff an element in as the payload, probably just supporting the most obvious string representation of the number.
As for Ignition, it has come up several times, and if it becomes a 'standard' or at least a defacto standard, then yes I'd say we'll do it. We have chased new stuff before only to waste a bunch of time on stuff that fell by the wayside, so we are a little more reluctant now to jump on every new things that seems interesting.
I will have someone here look into doing an app note and/or sample project that would generate/consume Ignition-friendly payloads.
