The problem I see there Perry is that a shock absorber is not a spring assister being designed primarily to dampen rebound reaction so will only have limited effect effect on the dynamics of a sudden compression over a bump and less still on a longer duration compression. Tightening an adjustable shock absorber to the point where it limits bottoming out would maybe create an unnecessarily stiff ride at other times. That's why I suggested above you need both dampers and bump stops. If you wanted to narrow the cure down I would have started with bump stops first.
I appreciate that but if the shocks on the OP car are in fact weak, that would cause the bottoming out. I am basing my input on the fact that while mine did bottom out from new, it was on extreme undulations or me being careless. The adjustable shocks I had installed are set a few clicks up from the softest setting, so far from the stiff side of things and actually, it is more comfortable now than with the factory units.
A bump stop IMHO isn't solving any issue that might be present in the shock absober itself or the springs for that matter. I personally would be hesitant in installing a bump stop unless the car was sorted where it didn't bottom out in nominal day to day driving without them.
