I switched to wired charging with the phone mounted in the same spot and the heat issue went away. Wireless charging produces a lot more heat than wired.

That's really quite interesting. I know the wireless charging uses more power to deliver less power, so there's heat generation due to the loss of power in the transfer (I'm assuming that's how it works).

But, I figured that the battery would heat up more the faster it's being charged, and so wired charging at the same wattage would heat the battery more than wireless charging.

Must be a lot of power->heat transfer loss with wireless charging.