G30 but only for specific axis

I would use a remap.

Most machines remap m6 to a macro program and contain all the g30 moves for the programmed atc position.

This way it does not rely on the cam system to output the correct code

I keep getting an error code that the modalgroup is incorrect. Can the 0 group not be remaped?

G30 is not listed as a remappable code: linuxcnc.org/docs/2.7/html/remap/remap.h...map:remappable-codes

It does not seem like it is possible to not have G30 attempt to move your A axis
linuxcnc.org/docs/2.7/html/gcode/g-code.html#gcode:g30-g30.1

The simple answer is probably not to configure the tool turret as an axis. After all, it isn't one....

is there any feedback about turret position from the turret?

The carousel component and a velocity-mode stepgen are likely to be part of the answer.