On the flip side of that series of considerations, however, is that if you're right and this is perfectionism manifesting as slower processing, then placing it under greater LOAD is likely to be a good thing in the long run.
The greatest problems for our own perfectionist were definitely when she felt that she should be able to attain it. If it truly felt out of reach, that made it better and enabled her to take more risks and focus less on the lack of perfection in the results.
Acceleration is definitely of benefit in that sort of situation, even the asynchrony makes it hard. If you think that applies, though, I'd strongly emphasize that you probably do NOT expect "accommodation" for something that isn't really a disability, but a quirk of asynchrony. The reason is that accommodations may place perfection back within reach, and offering them in the first place risks communicating to your child that you EXPECT perfection, since you're committed to placing it within reach, even using external modifications as needed to make it so.
Does that make sense?
The only skills that DD has never thought we expected perfection in/with are the ones that she has had to struggle a bit with-- motor skills and writing. No, she isn't exactly disabled at either one, at least we don't believe so-- she's just not got those as areas of top-1% ability. They're weaknesses in her particular profile, in other words. We've opted not to level them for her. I was unsure about that decision for many years, by the way, but in hindsight, I think it was the right thing to do.