Interesting
Although the MDA is based on obstacles within an area defined by tangents connecting circles draw around the runway thresholds, it occurs to me that the obstacle clearance of the let down procedure itself also interferes.
With this in mind you could expect a different circling MDA, limited by a VOR let down Rwy 09 circling 27 then on an ILS let down 27 circling 09.
I am puzzled