@seniora the board supports multiple batteries and multiple radio modules.
When Vcc goes below 2.7V (BoostThreshold in the sketch) the booster is turned on and stay always on, while when Vcc is > 2.7 the booster is turned off and stay off. This is the case of a fully charged CR2032 battery or 2xAAA disposable (Alkaline) batteries.
With 2xAAA rechargeable batteries (NiMH) Vcc is max 2.4V so the booster is turned on by the MCU.
The ME2188 works well with RFM69 and 2xAAA rechargeable batteries (Vcc < 2.7V): no false positive in the PIR and good range for the radio transmission. See below that in the night with no motion the pir stay off (clear) even if the booster is active.
With the NRF24 radio module and a CR2032 battery I have some (not so frequent) false positive in the PIR, but the booster here is always off (VCC > 2.7V), so this may be caused by something else. Searching around, found this.
Probably is the 2.4 Ghz RF signal of the radio module that triggers some false positive in the PIR!
In fact I observe this false positive when the node wakes up by a timer interrupt and start sending data.