anyone who is familiar with fiberglass layup will tell you that if you have stress cracks like the ones that are showing, there is definitely a problem at the lower end of the support. what shows at the top is only a symptom....
it is possible that the manufacture thought the liner was built strong enough to take the load, but its obvious that it is not doing its job....
AND.... this comment, "I wouldn't want to place any stress on a portion of the hull or keel where none was designed for or intended to be" , in both posts, the photos show that the liner is already acutely setting on the hull/keel.... so why not raise it back to its intended position and bed it properly so the load is spread over a larger area?.... just because the manufacture had a flaw in their design doesnt mean it shouldnt be repaired to remedy it.
some of the earlier Cal boats had a steel beam that spanned across, and it set directly on the hull and took the load of the compression post thru the liner.... due to corrosion issues they did away with the beam and used more layup and a supposedly better design of the liner to get the necessary support. it doesnt appear to have worked so well on some boats.
so if you feel my previous idea is a insufficient method, then you could just pop the liner out and reinforce it with more layup, or a beam....
one has to remember that over several years, under a load, fiberglass can give and settle a bit, and it absolutely will if it is lacking in enough support, and the only way to remedy it is to give it the support it requires.
so you can shim the top of the post to raise the cabintop, and leave the rest under stress and sagged out, or you can shim the bottom of the post and do the same thing.... but if one wants it done right to releave the "un-designed" stress from the cabintop, the bulkhead and the liner, it needs to have its support from below. and it will stop the stress cracks from progressing also.
my 34-III has the liner fiberglassed to the hull, as this gives rigidity and support, which is what is needed for good solid boat construction, so essentially it is "setting on" and bonded to, the hull...