I'm not dead and have gotten to pick this project back up after a long time.
My current work isn't really ready to post, I'm still getting back into the swing of Arduino stuff again. Currently I'm looking at i2c-based IO expanders to consolidate some of the I/O pins on the Feather controller, maybe to allow 8-pin control of the TFT display.
The new Tricorder is still a to-be-built, I had to scrap the main board I was working on but the sensor array is still partly assembled.
It'll probably be a while before real updates happen but I still want to make progress on this.