What's your budget?
Considering your heavy usage, I might recommend a LCD display to avoid any potential burn-in over long term use. I do realize that burn-in is NOT a major issue with the OLED devices, but it might not hurt to just avoid it with that level of usage. That would also allow you avoid potential issues with the eye-strain and headaches that a small percentage of users experience with the OLED display.
I would also recommend choosing a device with a larger battery and, therefore, better battery life. The lower number of cycles you put the battery through, the more life than you will get out of it. The easy answer for your use case is the XR, or, alternatively, the 7+ or 8+.