Isn't Plan Flaw the topicality "it's/its" shell? Regardless, the context of this question. is inherently contradictory. Here is why.
If a "K aff" has a topical plan, there is no argumentative incentive to run framework.
If it does not have a topical plan, there is no way to run "Plan Flaw"
You should ask the debaters who gave you this advice to explain what they meant by creating a double bind between Framework and Plan Flaw, since those arguments do not have only one definition in CX debate. Since this advice seems sincere, you should probably take a look at their shells and see how they run the double bind.