@blom Hi, if you want to run two gateway on the raspberry GPIO, it is possible but it requires some configuration steps. You can find some info here in the forum or you can see here how I have done it for the d-diot board (check basic system and MySensors pages). I have used an RFM69 radio module in combination with Nrf24, but it should work also for an rfm95, if the wiring is the same.

@blom yes, if you hack the library or use tekka's experimental version at https://github.com/tekka007/MySensors/tree/SleepTimeLeft

Looks great! Would love to see the schematic and 3D print file for the enclosure. @Blom Would you be able to share them?