Had it up and working from my Mac via the USB cable within 5 mins using gpsd and with with the Compute Module 5 again very easily. Alas my Waveshare case can't close with this hat installed but thats not the fault of the HAT. I've switched to using a Raspberry PI Zero 2 instead whilst I think about my options. As expected I only get GPS locks outdoors with the GPS antenna included, not indoors. It uses very little power - I'm using a large USB battery pack to run both the Raspberry Pi Zero 2 and the GPS module and I'm getting over 90 minutes out of it. More than enough for a site survery of a 14 acre wood using a telescoping rod.