We need to obey the federal register for alarm and periodic transmission above 70 MHz:
https://www.law.cornell.edu/cfr/text/47/15.231

This dictates the direction that some features need to go.
However, it seems we can emphasize alarm conditions and send some battery state when switches are human actuated.

Delay between different packets (guard time) was increased a little to improve receiving at sonoff r2 v2.2.

The code needs to now be mostly unchanged so that reliability testing with different receivers can proceed.
Also the consequence on home automation software of including a packet count in the upper four bits of the sent code needs to be considered based on user reports.