M303 PID tuning not supported?

I tried to run a PID Autotune using M303 E-1 S80 C5 S1 to calculate and use updated PID values since my heated bed has changed a little bit. Seems like the printer doesn’t respond to this command. So M303 isn’t implemented in the latest firmware?

I’m using a ZiFlex surface inside an enclosure that has dynamat installed. So the thermal characteristics are a bit different now, I suspect that if I was able to run a PID Autotune for the bed, that the heated bed could heat up more quickly. I also have a 240W (24v / 10A) larger capacity power supply because I didn’t like how hot the orignal power supply ran while printing.

With the larger power supply and the enclosure, it would be nice to have the heated bed heat up faster. What happened to the V1 design and firmware being released as open source since Snapmaker is not going to make it upgradeable like originally promised?