Usually light weight and aft CG
Presumably you need to measure it throughout the range of permissible CG?
Vmca will be highest at the most aft CG, but does it necessarily follow that Vmcg will also be highest at the most aft CG? If CG is very aft, the assistance given by the nosewheel (even unsteered) to directional stability will be highest. I am therefore wondering whether an aircraft with a very long wheelbase might actually record highest Vmcg with the CG not at its most rearwards?