Feedback targetFrameRate should still be applied when vsync is on

Just because Unity thinks that vsync is on doesn't mean it's actually on. There are common situations where whatever setting Unity is trying to enforce will be ignored: driver settings, adaptive sync monitors, window managers and so on can all override it.

In this situation the frame limiter will be "helpfully" turned off since vsync is supposedly doing its job, and you could be left with a game running at 3000fps. I want a way to set a sensible limit in that case.

I don't think it's redundant at all to have a frame limiter that works independently of vsync. If somebody doesn't want or need it they can just set it higher than the vsync cap or turn it off.