Hi Gonzo72,
It does seem that you desire a bit more surface firmness, but still allowing some “bending in” to assist with your rib sensitivities. I would still be interested in how you would respond with your current configuration using the 30 ILD topper over the 20 ILD, as this would provide a bit more of the surface firmness that you responded well too, but not as firm overall as the 6" of 34 ILD when you flipped your current mattress over. It seems that the “deep support” isn’t your issue as much as the “surface support”. There is also more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel” that may be useful as well.
Phoenix