Not sure what you are saying...;-)
I know and respect your initial findings and they were the reason I started a designated 32bit thread and I have had great luck changing my 32bit printer with commands. I know the heatbed commands are not in the documentation, hence my proposal to ask for it.
Different people have had different luck with Anycubic support - I think it depends on who you get connected with and possibly the tone in which you are asking. The times I have talked to Anycubic, they have been very helpful. That said, I have also reached out to Chitun directly to ask more info about their G and M cones and the person there was utterly unhelpful.
As such, I still think it's not a bad chance asking Anycubic directly about the right M-code. The worst thing that can happen is that they don't share it and you lost 3 mins of your life writing an email;-)