I thoroughly applaud your approach.

I've been dealing with some cardiac issues that were brought on / exasperated by a covid infection, and it's been challenging finding solutions that let me monitor my own biometrics while hiking without sending anything to the cloud. It's shocking that it's a non-trivial endeavor to pair a medical grade wearable with a smartphone and get differentiated granular alarms / alerts for user defined events (BPM within user defined bands, blood oxygen levels below a certain threshhold, etc..)

If your python SDKs work wirelessly, I'd seriously consider creating a RPI based system to do those things and be able to leave the smartphone at home while I hike.