it’s totally possible that only a biological brain can produce minds as we understand the word “mind”.

Bollocks. Thought is a process, like math. Nothing meat does with signals is impossible in other substrates.

At the utmost extreme: surely we can simulate physics at whatever level is necessary for virtual brains to function. Physical neurons are not gonna rely on quantum chromodynamics. Mere chemistry will probably suffice.

And hand-waving things that are like-minds-but sounds like Chinese Room nonsense.