I do lots of testing of apps in real phones, not emulators.
The thing is that the phones must be connected to the PC all day. Because of this, phones battery get swollen and I have to buy phones regularly.
Do you know any android phone which can be connected and on all day all week without getting swollen after a time?
Must be real phones, emulators are descarted.
What about if you remove the battery and keep the phone connected?
I think this might work with some phones but I tried this with my old Note 4 and it won’t work without the battery terminals on the phone reading some nominal voltage. I had planned to use it as a screen to control my 3D printer and after it didn’t work initially, did some googling and saw suggestions about newer phones being able to run without a battery (though no specific models given). The Note could work as well with something like a buck converter attached to the pins and powered separately.