These non-flair comments are common, but contribute nothing. I suggest they be subject to removal.
Clarifications. If you can't answer the question to begin with, you can't clarify it for people who can.
Tangents. "Follow-up question to the OP:...". It's not a followup if no one has actually answered the question yet, it's just distracting from the question asked.
Re-directions. "I don't know anything about this subject or history, but I think this might be a better question for..."
So rule of thumb with top-level follow-up questions is that to be allowed to stand, they need to hit the sweet spot: they can't just be restating the question with new words, they can't be so obvious that any answer to the main question would obviously touch on this to be allowed to stand anyways, and they can't be so far afield that it really is a new topic. If you see those, report them. We'll remove them. We do allow follow-up questions in the top-level if they are closely related to the topic, but provide an interesting and novel angle that substantially adds something to the original question being asked.
Follow-up question for the OP: How awesome are the Ask Historians mods, even if some low-effort comments make it through? On a scale of 10/10?
To get a handle on clarifications and tangents, I'd like to ask OP or anyone's opinions about a specific case.
Someone today asked "Thomas Jefferson and His Agrarian Republic" , with the body
When Thomas Jefferson or any Democratic-Republican was in office, how were they able to maintain agrarianism in the American Republic?
I replied,
If I may ask a follow-on question: what was the "agrarian republic" idea?
because I've heard the phrase but I'm unclear about what it meant. OP or anyone, do you think my question was out of line, and if so, can you explain anything specific about why? Should I have asked it as a separate top-level question, or just not asked at all? Considering it now, I'm thinking that any good answer to the original question should start with "To discuss how they maintained 'agrarianism', we have to first discuss what 'agrarianism' even is.", so maybe it's redundant?
May I suggest that "this might be a better question for ..." can be a reasonable response if it's pointing to a good-quality subreddit? I see an analogy to "FAQ Finder" posts. There is a "history network" of subreddits, kind of 'sister subreddits', listed in https://www.reddit.com/r/HistoryNetwork/wiki/listofhistorysubreddits . For some questions, the questioner might get more and better answers from places like (for example) /r/AcademicBiblical and /r/AskAnthropology.