My dd skipped a "bridge year" as well -- 5th, which is the last year of elementary here.
Our hodge podge math sequence has kept him moderately engaged for the duration, but again....all of this is really just a compromise. And now, even with his current placement, he's not exactly breaking sweat to maintain his grade.
That's pretty much what I'd say for my dd in most areas, too. She has had a combo of A+s and As throughout middle school with mostly A+s in her strong subjects with very little effort other than time. She has a large quantity of work, but it hasn't been hard for her.
In 6th grade, she had some catch up to do in math due to skipping that year and it being a subject that comes less intuitively to her and she did work to keep her A. There have been a few other times where that has been the case throughout middle school in math as well -- such as the start of this year in Algebra b/c the teacher seemed to be approaching the class as an independent study endeavor for the kids with little instruction on her behalf. Once the teacher got more engaged in teaching, she's been keeping an A without much work but it isn't an A+ and I'm sure that she isn't the strongest student in the accelerated class.
I'm really hoping that high school, like you saw with your oldest, is a step up in terms of learning but not a huge step up in terms of quantity b/c large amounts of work isn't a good fit for her.
