Could a non-black person even present a paper on afro-textured hair, without being subject to the vicissitudes of the social-justice-twitter-sphere?
The answer, typically, is OF COURSE. Big time. It would be well appreciated by most.
That being said, I get where this perception comes from -- there can be, as you call them, outsider social-justice folk who might try to say something weird here:
But I just need to highlight the "outsider" part of that -- if only for non-black folks to understand and to try to pay attention to exactly who you're listening to and getting authority from? I hate to use a phrase like "real Black people" but I'll go with that for now; real Black people tend to be the MOST reasonable, but often under-heard.
I'm reminded of, e.g. police reform; I understand that it's incredibly important and necessary. Which is why phrases/ideas like "Abolish the police" and "ACAB" are deeply unhelpful.
(and as always, I am only one Black person, nothing I say here should be taken as gospel for everyone, I could be wrong)
Unfortunately, moderation within a biased status quo doesn't achieve the goal of eliminating the bias. Those seeking a radical change can't reasonably be faulted for using radical rhetoric, only for wanting to change something that's "working."
I'm assuming you won't think this counts either, but here's another paper they reference that includes afros, again written by non black authors: https://graphics.cs.utah.edu/research/projects/sag-free-hair....