>Something just seems off about you compared to by interactions with furfags and latter /co/blr communities. Can't put my hand on why. I'd say that some of y'all give me vibes of furfags and seem to be on the spectrum /co/tumblr/twitter but others seem to be just ponyfags and I can't really describe why that is to me.
I personally don´t invest too much time at finding the differences between those groups. Yes, you can claim that bronies could be a derivative part of the furry fanbase, which is partially right (watch out, I´ve said partially). That statement from you would be correct if we are taking into account that MLP content is accepted in sites like Furaffinity or E621.

However, we are not taking into account that the term furry catches everything related to animals at making fan art out of it but they are undefined and don´t know where exactly they are going for. MLP has anthro material but that happens with any other franchise and the fur skin isn´t exactly all that popular (instead, anthro is a more human like body for the characters). The rule 34 might look similar and even furry artists use all the fan art sites to promote their work indifferently (even Twitter or Pixiv) to their convenience, so the differences kind of dissipate after delivering their content everywhere. Besides cosplaying as a fursona, could you tell me anything in their culture that makes them unique or peculiar? Because I have visited the Furaffinity forums at times and a few topics between the users were quite average and if you told me that they were furries beyond the site or their avatars, I wouldn´t find any substantial differences from any other guild/group except for superficial/anecdotic stuff. Unless you tell me about the drama, try to tell me how different one fan would be from the other.

Besides, the anthro style has become so popular that it has become from a niche thing to a style for drawing to any franchise. You could say that MLP is furry but that would be like saying that Pokemon does for having the same style in the fan art, but so would do any cartoon basically. The rule 34 was once a taboo but considering that there is so much material these days and how normalized has become, some fetishes that were seen as degenerate or niche, they have become vanilla for those who are into NSFW (and even get boring or sick of seeing so much of it). With the anthro body, the same has happened in general.

/mlp/ doesn´t allow it but recently, I´ve seen a thread in which a few anons discussed seriously that they could post and accept it perfectly, just that they pretend to be triggered in the board in front of the public or create artificial drama for the mods when in reality, those same users have been using Derpibooru for that content they are "complaining" about.

What does really matter in the end? I would worry more about the quality of the picture themselves rather than trying to find a stereotype in terms of uniqueness. MLP has its anthropomorphic characters as well so trying to be unique and establish difference in this regard would be quite stupid and delusional in the first place (pic related)

About /co/mblr and mainstream social media, I have less of a clue but yeah, /co/ and /mlp/ split themselves in mindset long ago. About the behavior in social media groups, I lack of enough knowledge to comment about the patterns shown over there.