What you're saying makes sense since what you're signing off is not specific to the training method. I understand that as coaches we are allowed to teach parts of the SIM that are not part of a training method (AFF, S/L etc...).
So things like equipment checks, canopy skills, landing obstacles and any other parts covered during the ground course, should be able to be sign off by a coach. Anyhow if we teach it , why can not we evaluate it?
Very good point.