Slid the radar module into some heatshrink sleeve, powered everything from a usb powerbank, and tried a few sensitivity tests... it still senses reliably up to 5 or 7 meters away even through the sleeving.
Sat it on my campers dashboard, and it reliably detected movement through the triplex glass windscreen 1 to 2 meters outside the vehicle.
That's quite a significant result, because it means that sensors could be placed inside vehicle windows to provide perimeter approach alerts if wished.
Similarly for household use, because it worked from behind wood panel doors, under tables, under counter-tops, and behind glass windows.
Module alert timeout is 2 seconds - continued retriggering extends the original alert until 2 seconds of inactivity timeout. The timeout could be changed by changing a surface mount capacitor, but it would be easier done with software in Esp-Basic.