Polonius put it best: “Unto thine own self be true.”
There should be no titles that don’t begin with the word “acting,” at least internally. I come from an organization that has real titles, real pay grades, and then acting titles with other, lesser pay grades.
More to the point, and more realistically, we are all acting. I’m a debt collector. But in all honesty, I am only a collector so long as I continue to act as one. Frankly, if I fail to do so, I lose my non-acting title. So again, I am only a collector so long as I continue to act like one.
So long as I act like a collector, I should get paid as one. So by the same token, so long as someone is an “acting supervisor” they ought to be paid exactly as that: an acting supervisor. An acting CEO… ought to be paid as such. And should lose the title as soon as they don’t act like one.
In short: rank is as rank does.