[rz2k]

The maximum memory configuration for the M3 Max MBP was also128GB.

[storus]

That's my whole point. M3 Max 128GB -> M3 Ultra 512GB. M5 Max 128GB -> M5 Ultra 512GB. But if M5 Max 192GB -> M5 Ultra 768GB, i.e. Ultra having 4x the memory of Max.