No doubt, it takes two moves if the safety is on. Again, I am not discrediting the use of a manual safety.
My whole point from my first post is, I believe it to be unwise for a person conditioned/trained to carry only pistols without a manual safety to be advised to carry a manual safety gun by simply leaving leaving the manual safety in the off position.
In casual shooting and hunting, I've seen people that have a gun with a manual safety carry their guns without their safeties on as a practice. Considering the type of guns they were carrying (single action), I consider that very unsafe. I've seen those very people accustomed to leaving their safeties off, miss a shot because they went to pull the trigger on target and "somehow" the gun safety was on. They were conditioned to not sweep off a safety and missed a shot (hunting). That was their fault and misfortune.
If this were to happen to someone that carries concealed, the fault and misfortune could harm the shooter trained to carry a non-manual safety gun.
My belief is if a person is going to dedicated themselves to carrying a manual safety gun after years of carrying a non-manual safety gun, they would need to train for that gun. There is some quote out there about "reverting to your level of training under stress".