Something else worth noting is that there is evidence that HW4 may be used in different configurations for different vehicles, or even possibly different specifications. So there may well be a different configuration for SX3Y and a different one for CT or even truck.
Purely speculation, maybe that an FSD equipped car will get a different configuration too - in early days, Tesla certainly said that EAP/FSD used more cameras than regular Autopilot, although that distinction has long gone. But not unreasonable to think that sensor capabilities needed for EAP and/or FSD may be different to regular Autopilot and saving a few $$ on not fitting an unneeded sensor may well now be a factor.