So, I just found Papyr.
Raytac MDBT50 module with Nordic nRF52840 BLE/802.15.4 SoC 1.54 inch 200x200 pixel red/black/white epaper display - GDEW0154Z04 CR2477 coin cell holder Micro USB (device) RGB LED NFC (PCB) antenna Push button USB/Battery power switch Extra GPIOs SWD Programming header Mounting holes
I am looking for a similar device, but with BLE5.1, for it's AoA/Aod Location features, so that I can use it as a tracker.
Any small (dev) board with at least BLE 5.1 will do (I am processor agnostic), but it must support a display - either eInk or OLED (even TFT), but preferably something battery friendly - and it must be either on-board or easily connected with something like a Grove connector; absolutely no soldering or hardware knowledge required (would Arduino compatibility be an idea? Probably plenty of snap-on displays).
A major bonus is an on-board debugger; failing that ability to us a J-TAG probe would be welcome.