1. > The term "blend mode" is a term of art in the industry, yes.
2. > For example, we could have had "display-mode" rather than "display", but that would definitely have been redundant.
3. > The few exceptions are things like pre-multiplied RGBA, where the RGB components depend on the alpha. But these are rare.
Yes, because RGB isn't RGBA. If anything it should be RGBA with an optional alpha. Because you know, that's how the _structs are formed to begin with._
And separately,
> Given that the CSSWG's membership is largely browser implementors, I'm pretty sure we have a handle on what the fuck our graphics stack does.
Yes, as far as the people who actually write the portions of browser code that involve placing pixels on the screen. You however, clearly do not.
I'm not sure what you're doing in a spec committee; you don't sound like a person who has any experience writing low level code regarding these systems. Given this, it's worrying because I'd wager that you'd make uneducated decisions affecting others based on this lack of experience.