I just created a quick object with a single parameter called iAmMirrored (Boolean) and put the following in the Master Script:
parameters iAmMirrored = SYMB_MIRRORED
I can then add the parameter as both a criteria and as a display field. The only parameters that are greyed out for me are heading parameters.
I can't see anything in the standard fields that displays the mirrored status. Could be good to add this as a wish though as I can see times when it would be useful.
AC24 (7000 AUS FULL)| Windows 10 Pro | Intel Core i7-12700 @ 2.1GHz | 32GB RAM | NVidia T1000