Stay awake while charging, bad for battery? Is it bad for battery to use the option to stay awake while charging? Will it make my battery drain faster in the future?

PD: I use my phone for app development. I have activated the stay awake option to avoid unlocking the phone constantly.
As long as the battery stays below 140 deg F, the extra heat won't damage it.  See retailers' instructions, manufacturer's data sheets, or any professional drone pilot. If anything, the battery works better at somewhat above room temperature.