So basically the existing word "racism" didn't fit (because racist Brits would hate Asian HKers just as much as brown Syrians and black Africans) so you invented a new completely concept but conveniently attached the word "racism" to it for maximal emotional impact?

Despicable.

Though I think nationalism may be at least as much of a factor as race-based differentiation. (That is, that nationalism in the context of colonial history is why HKers are treated more favorably by opinion than other non-white, or even white, immigrants.)

Though, as explained already in GP, I think nationalism is the more relevant factor here, whether or not racism (binary or differential) is also involved (which at some level it obviously is.)

I didn't say it was. I said that the upthread commenter’s use of “differential racism” to describe their explanation in which Britain was doing that was, contrary to the claim that it was redefining “racism”, a perfectly valid use of the term “racism”.

I've also said in every post in which I've argued that point that I think that what is actually happening involves nationalism in light of the HKs colonial history, not, or at least more decisively than, racism, differential or otherwise.

There two different issues here, one about whether a hypothetical scenario is within the usual definition of “racism” and one about whether than hypothetical is the best explanation of what is factually occurring.

No country can invite everyone to immigrate. They have to be selective, and that doesn’t make them racist. No one has the right to immigrate to another country: it’s a privilege granted by the government and people of that country who make decisions about who to accept according to their own interests and perceived obligations - again, not racism.

Having said that, the GP does not provide any evidence that racism was the motivating factor here.

That was exactly the point.

Even a racist as extreme and obsessed with whiteness specifically as Hitler deemed some nonwhite races worthy of respect, even as he plotted others' extermination. Clearly it is absurd to define 'racist' so narrowly that even the actual Nazis don't qualify

Is it possibly more representative of your own prejudices that you see only negative motivation here?