BTC mining isn't memory-bound, it's compute-bound. The more sha256 hashes you can compute per second, the better. And I'm highly doubtful that any general-purpose hardware at all could even begin to compete with mining ASICs.

Would you or someone happen to know/guess the hash rate of the M1 Max?

I don't think there's a definite answer to this. There's no existing bitcoin miner software optimized for Apple hardware. So, do you use the CPU? The GPU? Both? If you do use the GPU, which API do you use to program it?

At this point it doesn't make sense to mine BTC on any GPU.