A little bit to late but you write that you check it sometimes.
I do not really have any experience with mooring at drying docks (even though I bought the boat in Southampton). But I do not really see the difference between the different keel configurations. You still get the same stress at the hull. I do not know how it will work if there is deep mud but that is another story :-)
BUT if we disregard the mud you should bear in mind that all yachts are built to be able to stand on the keel. Ofcourse you will need something to balance the boat so it doesn't turn over on the side.
I can only give you my experience with a First 32s5 in Sweden. Here most of us bring down the rigging and lift the boat on shore for winter storage. I experience the 32s5 as a bit back-heavy when standing on the tip of the keel. Partly because the keel tip is rounded. It makes me a bit nervous thinking about winter storms and such so I usually put a support in the aft. As you can see on the second picture here
When the picture is taken it is April and it has been standing there since October (of course with a cover on top).
That would indicate that if leaving the boat at a dry out dock you should tight it up properly to the dock. She will probably not tip over backwards but you will get a uncomfortable lean backwards.