I don't think that there is a system for this. Leaving a comment to that effect on any new question might be the best available option.
For this specific case, the user in question seems to have a view of the situation along the lines of "everything is fine, except for these dozens of exceptions", and has explicitly rejected advice that strays much outside of each individual question. I don't know how much we can do to move beyond that while trusting the information the OP has posted and respecting their intent.
If the user were active in chat or more frequently utilizing the sandbox it might be easier to address this meta-quality to the set of questions, but I'm not sure that's much better than commenting on the posted questions.
But more broadly I don't think it's such a bad thing. While it's fine to try to nudge people towards asking about the problem we think they are really having, or to ask a question that "summarizes" their other questions, it's not hard to imagine someone in a less-than-ideal situation that has lots of scenarios in which interpersonal skills come into play. Their questions may be related in that they take place in the same setting and with the same people, but it's still possible for each question to be about a distinct IPS scenario and be useful on its own (to the OP and to future browsers).
Finally, I think that we should allow some leeway for situations like this one. The proliferation of seemingly related questions might irritate some, but it can be harder to see a situation fully from within rather than with an outside perspective. And, someone coming to IPS.SE might have a poorer-than-average ability to assess and appreciate the "true" situation, making it hard for them to see the commonalities that underlie each question and describe a broader, core issue (even if it seems obvious to other IPS users).
Engaging in comments on questions is a bit awkward for this, but I'm not aware of much else we can do.