I was thinking of the standard definition of parasocial as reflected here:
What Is a Parasocial Relationship?
So while in-person relationships in real time and space, or online connections with a person one actually met at one point, can definitely be one-sided and have power dynamics, they wouldn't fall under the current definition of parasocial.
But in the sense that the concept of media is changing, with so much content from so many sources, including completely non-famous individuals who still use media platforms, albeit for small audiences, perhaps the idea of parasocial will expand.
People do offer tiered access to increasing parasocial connections, such as YouTubers or podcasters offering additional content on Patreon, some of which may include more direct interaction. That's somewhat more like Only Fans in the sense there is another barrier to interaction, however Only Fans in particular offers not just whatever the end content and interactions are, but the promise of what they may be.
Sometimes people buy a fast food item because of the advertising, even if they know there has been food styling using inedible materials like the perfect scoop of ice cream made from instant potato flakes. Sometimes people just experience the disappointment of what they received versus what was promised.
I recall Subway got in trouble because some of their "foot long" products were not. Overall, there is too much leeway with marketing in my opinion. And I don't think just because something may be considered a fast food product, or a leisure/self-indulgence product like OF, that rules should be slackened. If anything, they should be stronger because consumers are in a more vulnerable state when shopping for those types of products.
Back to the social aspect, you may or may not watch Star Trek. In Star Trek Voyager, the Captain had an intimate relationship with a holodeck character at one point, which essentially is generated by the ship's computer to certain specifications. Without going into total detail on the plot permutations, though some could be helpful to consider, the ship's doctor, himself a hologram, albeit one with an exceptional matrix, self-awareness and growth over time, told the Captain that while the hologram was not a real person, her feelings were still real.
So in the sense that badly written OF responses can break that illusion of actually communicating with the model, so too can they break the potential for a parasocial relationship. Yes, those are one-sided in an emotional sense, but even that one side may be blocked from happening in that case, even more so than if the person never responded in the first place. Because by not responding, they would maintain the possibility of them eventually responding with just the right thing that would ping those emotions.
I think when someone messages an OF account, they should not assume they are speaking to the model. But I think it's fair to hope that a response would be in the voice of the model. That voice could also be expressed by them in the text that goes along with posts, their general description, what they say in videos, and to some extent what they do.
They could promote this parasocial opportunity by calling out subscribers in posts, saying a subscriber encouraged the to do such and such act, or that they get dozens of messages saying how much people liked such and such post. None of those things may have actually occurred but it gives the illusion of engagement and responsiveness and maybe would increase actual engagement.
As for how I would respond, it would completely depend on the voice of my account. Otherwise I would vamp. Your message has an air of romance so I would probably try to blend that with something on the sexual side, like some talk about 1950s clothing we would wear. I would not focus on the actual plot of the movie which included the accident on the initial day they were to meet on the observation deck. I would also go on a rant about how much I think Meg Ryan is garbage and Sleepless in Seattle is an overrated knockoff. But only if you had a fetish for rants against Meg Ryan and Sleepless in Seattle.
