It is a 'hot' topic. As mentioned above, the UCU (University College Union) which has been in the Press only recently, is an enthusiastic advocate for transracialism, and has included being able to self-id as black in its national policy.
In the US in 2017 Dr. Rebecca Tuvel addressed this question in her paper;
In Defence of Transracialism
It was originally published in the feminist philosophy journal Hypatia, but a social media pile-on resulted, provoked by the editors themselves, suggesting that the subject hit a very raw nerve amongst the advocates for self-id. Dr. Tuvel's experiences after the original publication is detailed in her interview at People were absolutely vicious towards me
Notably, amongst her critics and online abusers were a number of self-declared bigots , similar to those who are currently abusing Dr. Kathleen Stock (also a feminist philosopher) and who made it clear that they have not read the paper in question;
Many people who signed the letter and commented on the paper admitted to not having even read it
(extract)
In this article, I argue that considerations that support transgenderism extend to transracialism. Given this parity, since we should accept transgender individuals’ decisions to change sexes, we should also accept transracial individuals’ decisions to change races. I entertain and reject four objections that suggest a society should not accept an individual’s decision to change races. I then turn to Sally Haslanger to argue for an account of race that allows for racial membership on the basis of social treatment, and, I will add, self-identification. I conclude that if some individuals genuinely feel like or identify as a member of a race other than the one assigned to them at birth—so strongly to the point of seeking a transition to the other race—we should accept their decision to change races.
After throwing Dr. Tuvel under-a-bus, and despite reorganised and later being taken-on by Cambridge University Press (and changing its Twitter account due to the adverse feedback it received) Hypatia is pretty much a 'dead' journal, not rightly trusted by potential contributors or subscribers and one that is not best seen adorning an academics coffee table.