FYI: I'm posting a non-sneer without an NSFW tag. I suspect that you might want to post this sort of article in the sister community !NotAwfulTech for non-sneering feedback; this community is explicitly for "big brain tech dude" authors who are posting "yet another clueless take."
While it would be pleasingly recursive to look at this article as such a "clueless take," I think it's clearly more well-researched than that. Also, while I personally don't like the concept of white allyship, I understand why it emerges: it takes longer to let go of one's beliefs than to embrace the people around you, and so it takes longer to let go of whiteness than to be okay with non-white folks. So, I'm not going to take that angle. I don't think it's okay to be white, but I also think that it takes a while for white folks to realize that they can stop being white.
With that all in mind, I think that it's worth pointing out that while all five suggestions are laudable, none of them address the structural and reputational problems at the heart of Mastodon. @sailor_sega_saturn@awful.systems had a killer comment on the last draft (which I can't permalink because Lemmy is trash; it's in this tree) about how ActivityPub structurally allows harassment by allowing pseudonymous interactions. In my personal conversations with ActivityPub's architects, I got the sense that they didn't understand what we call The Reputation Problem: the paths via which you give reputational incentives to participants will be reinforced according to their rewards. This is also the root of my pessimism about related projects like Spritely Goblins.
(This reminds me that I need to flesh out the bullet point in my notes headlined "The Reputation Problem & A Theory of Generalized Fuckwittery". This generalizes the Greater Internet Fuckwad Theory, Homo economicus, etc. It's all obviously connected from a distributed-systems perspective: bad actors are getting paid for their bad actions by the system's structure!)
Further, it's not clear that the community's adaptations are sustainable. TBS can't seem to shed its TERFs and it should be obvious that any similarly-structured project will be too authoritarian for a large chunk of the community. Hashtags aren't private or moderated spaces, and any sort of hashtag usage council would immediately run into the same authoritarian issues. One of the disadvantages of Balkanization is that your neighbors, safely separated from you by geographic obstacles, will start talking shit about you, and you don't want to let them police your lands.
Biologically, race isn't a coherent ontological classification; you're thinking of ethnicity/culture and heritage. Whiteness isn't a biological classification, but a belief system. Incidentally, part of whiteness is the belief that races exist and are meaningful classifiers, along with the belief that whiteness is worth defending, leading to white defensiveness, also called white fragility.
If you still insist, then here's a speedrun: are they white? Why or why not? The Ainu, the Inuit, Michael Jackson, the Scottish, the Irish, the Italians, etc. Whiteness is one of what George Carlin called "big clubs;" they are defined primarily by power-sharing agreements between political power brokers rather than by scientific evidence. The power of whiteness has been extended in various ways even as science has shown that it is bullshit.
Also, on a personal note, I'm routinely discriminated against because of the color of my skin, along with other physical properties. I don't deny that this happens to me or others, nor do I deny that it is a large part of our society (or at least the USA.) I merely opine that this discrimination is undesirable, unmoored from scientific evidence, and something that we should work to eliminate. I'm not pulling one of those stupid "colorblind" routines.