Neptune How to print above 260 with all metal hot-end?

So, I have a Neptune 3 Pro, and assuming I have an all metal hot end and all appropriate parts to print at 300C. How to I get the printer to accept the higher temperatures?

My understanding was I just run the gcode and latest firmware. This does not seem to work.

Failing that, is there a way to view a developer mode on the printer, or otherwise pull the logs?