not seen this command before but will certainly give it a try - which section of the MSFS calibration menu does it appear in and is it a button or axis? - will it just covert the whole throttle into a reverse throttle axis or does it just activate the reverser section of the throttle under the idle detent?
note the issue at the moment seems to be the sim/A32nx throttle calibrator sees the reverser section of the bravo (underneath the idle throttle ident as the same as TOGA i.e. full power!) - so when you try to calibrate the full reverser it creates a deadzone overlap.