> It is so culturally alien to them that it would never get through.
If there's a need then this will change. You might as well say that they'd never use a telephone because it's culturally alien. It was alien, but it was useful, so they adapted. Same with email and video calls. The boss has to log into their banking just like everyone else, because there's a need for it. If there's a need for this, the OP's suggestion seems like a pretty good one, as it augments the existing culture with a security step.
If there's a need then this will change. You might as well say that they'd never use a telephone because it's culturally alien. It was alien, but it was useful, so they adapted. Same with email and video calls. The boss has to log into their banking just like everyone else, because there's a need for it. If there's a need for this, the OP's suggestion seems like a pretty good one, as it augments the existing culture with a security step.