I don't absolutely need 16V. I'd just prefer to get there since my other components can handle it and it would make my circuit more robust.
The thing about this circuit I'm designing is it's for replica prop builders who don't know anything about electronics. Which means they won't know enough to select a power switch which can handle 5A, and they will want to do bad things like drive everything off a single battery, and they might be using an external amp which requires 12V and the battery they're using puts out 14V fully charged.
And though I can't protect them from every bad thing they might try to do to the circuit, I'm trying to make it as robust as is reasonable, within my space/cost constraints (the board is the size of a credit card) so they don't keep blowing chips up.
Also, though I don't expect they will even use half the power the board can handle 95% of the time, I'm still trying to design it to handle a full 5A 100% of the time just in case.