The only caveat I would add to this is: if you begin the position without the expectation of on-call being made up front, and then it's pushed on you without an

The only caveat I would add to this is: if you begin the position without the expectation of on-call being made up front, and then it's pushed on you without any extra comp, that's not exactly fair. However, as long as that's made clear from the outset, yes, your salary covers you performing your expected duties whenever they need to be performed. It's not like salaried engineers aren't compensated well.