Is there always a great reference for which way down is, given that the phone can be in various orientations? You might have to do some other heuristics / build some other model for that to figure out which axis to subtract your 9.8 m/s^2 from - maybe it's easier not to worry about it.
> Literally no one will sell you an eSim contract for just few days.
T-Mobile definitely will (I mean, you pay for x GB and minutes and it lasts a month, just like most prepaid setups). Just requires a download of their app -- I use it when I'm traveling to the states (my carrier in NZ uses a physical SIM).
One way to do that would be to look at outcomes of patients who have received the therapy to see if they feel their needs are met, like this study did.