I decided to convert the 100m range chime into a "product". As I use the RS-80N3 often without the radio, I also decided to make it detachable.

This one includes a switch for power (although the quiescent current is low, it probably drains the battery in a year or so) and a "chime switch". Sometimes the audible feedback is usable and sometimes it is disturbing.

It works like a champ and seems to have at least 30m usable range and works through walls as well. The only downside is that the chime is fairly bulky (for no obvious reason).