Lantirn, let's ask what is a circle-to-land. A manoeuvre executed at the MDA inside the protected area to bring an aeroplane to land. As long as we are talking what's legal, there is no mention to which runway or what type of trajectory is allowed. Thus as long as you maintain the runway or its (immediate) environment in sight, you're authorised (all other boxes assuming ticked, no matter how unlikely).
Admittedly some of the examples above are solved by a simple straight in landing anyway, so debating too deep is pointless.
Line-of sight obstructed by airframe parts does not sound as a show stopper. Leaving the airport behind in turn - I think that would be one.
Yet circle to lands are intended to get you to a non-straight-in runway in a low cloud overcast conditions. In good weather when the 3 deg CDFA is for some reason obstructed, ask for and declare a visual (still IFR proceudure) and get away from the runway in-sight restriction. Sorted.
Last edited by FlightDetent; 28th Mar 2019 at 17:39.