My goal is to get very good at 5-6 hour efforts. For that, a weakness in sprinting is not a limiting factor. If I do the scheduled FF in two weeks time, and it turns out that sprinting is my biggest weakness, I understand that the next program I choose is going to focus more on sprinting. I don’t really understand how that will help me get closer to my goals and wonder whether I shouldn’t do a HM instead.
The next plan won’t focus on your weakness. Your next plan will focus on your goals but adapt that to your profile.
If you choose a gravel grinder plan with a sprinting weakness, the plan won’t fill with Violator and The Shovel, it will still be focussed on getting you through the gravel grinder.
Doing that will only make sure it is the weakness
Exactly this. The plan is tailored to your 4DP profile, but the goal is defined by the plan you choose.