using an e-ink screen to be easly seen even in full light and need very low powerand display will update only when the ring is touched (capacitiv sensor) also to save powerit would be powered by a button battery on the opposit "side" of the screen
they also cast their datas via zigbee every 10mins (low power and long range but low bandwidth bluetooth)so from an app on your smartphone you could get notifications when a number overpassed or underpassed a certain level, or just changedso you could know when your coffe gets cool, or when someone drink some without permissionit would also have some settingsfor volum you can get imperial or metric units and what material you will put in the StaX with pre-made volumic masses or custom one(because it tells the volum just by weighing the inside and divide it with volumic mass)for temperature you can get imperial or metric too but you can also have both, or one of them + delta between temperature outside and inside
no .stl because there is nothing special on the model to see