My concern would be the makeup of the 2-year Algebra class - students and curriculum. Is it an honors class that combines Pre-algebra and algebra for top performing math students, or is it a class tha purposely strings out Algebra 1 so that not-so-apt math students ease into Algebra? Or is it the Algebra that most students take?
If your ds has been frustrated with the pace of his math classes, I'd be hesitant to simply skip a year and put him straight into another math clas that is either taught at the usual rate or a slower pace. Ideally it would be good to be able to offer him compacted math that he can pace through at his rate. Our ds is subject accelerated in math but it's handled then placing him in a classroom of higher grade level students who are on track with math and he is at teems very frustrated with the repetition and pace of the work.
Best wishes,
polarbear