(This is probably more applicable to the players who self-insert to at least some degree, including injecting their own preferences into the MC when it comes to physical traits they find attractive in a partner.)
I’m curious: Have you (as a reader) ever replaced a physical detail - or maybe even the whole appearance - of a RO with another in your imagination? For instance, if a RO was a perfect match otherwise, but their hair was described being a color that wasn’t what you’d have chosen if it had been up to you and isn’t that appealing to you. Or have you maybe even fully body-swapped them for someone you have a crush on or replaced their body with the body of a RO from another story? Or do you treat them as you would treat real people in this situation, by - worst case - simply not dating them and shrugging it off as something you can’t do anything about / isn’t meant to be?
I’m usually not able to change an image in my head as soon as it has been established, which means, if an author says right away character XYZ has hair color ZYX (and, sticking with this example, hair color is usually among the first things mentioned), then that’s how I see the character and there is little I can do about it.
But I openly admit, there were a few instances here and there, where I’ve tried, because I loved the personality of the RO so much, yet the physical appearance just wasn’t that attractive to me. Like many, I have a certain type, and while I’m a bit more open for men who don’t fully match it in real life, I don’t see a reason why I shouldn’t wish for “perfection” in this regard in a fictional story that serves me as a vehicle for escapism.
Yet I hesitated a bit before making this topic, because I’m fully aware there’s a certain type of fan who’d probably take offense to my position, because they love their favorite ROs so much the way they canonically appear that they would consider my position to be, I don’t know, perhaps rude?
Which brings me to the next question: How do you authors feel about this? While I generally think it’s none of other readers’ business how I imagine the characters in a game I’ve paid for, as long as I don’t go around claiming my interpretation is a better one or complain to the author and ask for changes, I can totally see why an author would possibly not be too happy about it. I know some feel very protective of “their babies” and this is something I can deeply relate to. I’m fully aware how much thought and love can go into an OC, down to the smallest detail, and I can see how it could be hurtful to have all of this disregarded for not being “hot enough”. Another, much bigger, issue would arise if an author did their best to provide a diverse cast of characters only to have a reader erase the e.g. race of a character (which is something I’d never do and where I’m drawing the line), but I would think those readers have a bit of self-awareness left and wouldn’t go around flaunting their fan art, but maybe I’m very naive here.