Perhaps have a standard letter where you change a few details, keep it mostly generalized so that it can cover pretty much every situation you encounter? Just to put them on notice.
I know that's a big nuisance and you shouldn't have to do it.
So I checked to see if there's an association for black/POC airline passengers, and apparently not. However, the NAACP has handled some of the relevant cases.
Apparently, however, it seems that fight attendants are having to deal with many MANY unruly passengers, to the point that their lives have been put in danger. These passengers, as far as I can see, are all WHITE and all ranting and raging about having to follow rules, such as, e.g., wearing masks for prevention of COVID transmission.
And alas, many black/POC flight attendants have suffered most from these unruly racist passengers.
Another approach could be to just keep records on every incident and collect them for reports to various agencies governing policies for passenger airlines. And/or report it to your company's human resources department. Or put it together for another article. And/or ask people to send you stories about their own such encounters. Or perhaps do a joint article with one or two other authors experiencing the same things.
Yes, I know it is tiresome and you shouldn't have to do this. But pretty sure you are not the only black airline passenger who's had to deal with it.
... So here I am "just" being my annoying, privileged white self telling you to do things you shouldn't have to do. None of this should be necessary.
I do very much wish you didn't have to deal with it at all.
Nonetheless, one of the more useful articles I found:
https://www.businessinsider.com/american-airlines-naacp-warning-black-passengers-2017-10
Pretty sure there are potentially several articles that would be of interest to some prestigious PAYING publications.
More work for you, as if you needed it. But who knows where it could lead for you?
Signed...
"Pollyanna" (that annoying upbeat positive white girl who actually in her normal life isn't all that upbeat...)