[to OP] That is prima facie evidence of the right half plane zero. So don't let anybody tell you it is not there. It is, and this is a well known fact. [to OP] I used a convertor with the same response to convey signals at frequencies approaching a small submultiple of the switching frequency. This used a compensating zero in the right half plane.
So far, so good.
That, I disagree with, having done much better than that, both analytically and in practise. If not for the effects that occur as the response approaches the switching frequency, you could bring the response poles arbitrarily to the left.
Not a bad analogy. Think about balancing an upside down pendulum. It is the same problem with respect to balancing the bike.
Good luck.