Anet A8 BLTouch and Bed heater problems

HowardTheDuck

I am setting up a Duet 2 Wifi on my Anet A8 and just updated the firmware to the most recent version.

On https://configtool.reprapfirmware.org/Start when I select Firmware version: 3.0 or later:
on the page I/O Mapping, under Z-Probe the Pin "PWM Control Channel (BLTouch only)" defaults to "(not assigned)"; should I change this, and if so to what?
on the page "Endstops" the BLTouch option is no longer available;

Also, when running the "Check Heater Functionality" test in setup, the bed heater rises about 2-3 degrees above ambient, then generates the following error message and stops:
Error: Heating fault on heater 0, temperature rising much more slowly than the expected 1.8°C/sec
That expected rate seems very unrealistic to me, using my stock board it would typically take at least 5 minutes to reach 70C from ambient which is closer to 0.1-0.2C per second.

How can I fix this?