Amazfit GTS 2 Mini has a barometer too
In my review of the mini I stated that the barometric altimeter app from the bigger models was missing.
But you can find it in the compass app on the mini. Launch compas, swipe up and wait a bunch of seconds to get the measure done ... et voilà !
This small and quite cheap watch really does have it all !
Thanks to Reddit user timochr for the info !