i think the idea of being able to engage a reblog (like add a caption) might be nice.
Yeah this has been brought up in the past as well, these may have to be "front-end only" addition however. Leaving comments could be a good solution for now saying something like "reblogging for visibility" or "reblogging cause I care about this" or "I don't really agree with this but reblogging for the discussion".
seems like a good alternative for the caption idea. Then I guess you'll just have to mention specific people you'd want to discuss the blog topic with 🤔 not that different from if you mention someone in a caption when you reblog something too