A bit off topic here, but our district is changing up the math sequence, essentially stopping math acceleration in 6th grade. So the normal acceleration of 7th algebra, 8th geometry, 9th alg 2/trig, 10th pre-calc, 11th calc ab or bc, senior year dual enrollment linear equations/diff equations is going away. Not sure what to think of it, except if I had an accelerated kid I'd be pretty miffed. The district is essentially forcing the accelerated kids to go outside the school to challenge themselves. Mind you, this is the district where the majority of teachers make $130k or more a year, and has decent affluence.
I'm a math department chair in a private school in an affluent town and I'm well aware of the dangers/silliness of acceleration.
Earlier in my teaching career, my school accelerated kids per need: which basically means we taught kids where they were at. That meant lots of parity within grades, sometimes kids in five distinct "classes" within a grade of 25-35 kids. At that time, we had five full-time teachers in the math department, so it was sustainable.
We're down to three full-time teachers now due to budget cuts after enrollment drops four years ago. We're now back at a healthy, sustainable number of kids for the size of our school, but our department hasn't yet seen the fruits of our budget increases.
That being said, this year is the first year we've streamlined acceleration: we build it in unit-by-unit extensions in fifth grade and then by sixth grade we start to solidify tracks for those who can handle it, more liberal at giving kids the opportunity at that age and then giving benchmarks to see if they can stick with it. If a kid "moves down" no problem, but kudos for trying.
That design is what you mentioned: 7th A1 & 8th Geo. If some kids in Geo deserve more, then they can pay for a CTY A2 course with the idea of entering Pre-Calc in 9th.
So far, it's been good, but there are still exceptions. We have a few kids entering 7th next year who will firmly start A2 and who genuinely deserve to take the class. The elephant in the room is: we've never had a teacher teach A2...but there's pressure to have that opportunity next year...as it stands, it looks like it'll be me since I tutor two kids in A2, but I am not comfortable teaching that level...if it comes to that, I'll renegotiate my contract for next year since it'll save the school a lot of money having me do that.
In conclusion, I'm not a fan of wholesale acceleration that is more than Geo in 8th grade. It's a race to nowhere and typically it's an ego measuring contest between parents to see who's got the smartest kids. Heck, I took Honors Geo in 9th grade, and I had no problem starting my college career as a math major (before I switched to English).
Personally, what's more important is for students to use the math and apply it to more critical thinking and creative usages. Doing more math faster doesn't equal success, but using math to think differently is so valuable, especially in the middle school level.
Also, I guess it's my turn to trash your 130k comment, but I'm probably just taking it personally coming from a two-teacher family who is making it work to stay within budget living in a modest, small home in Norwalk.
The only teachers I see living the high life are second career people or teachers with a partner who makes a ton more money. Teachers will never be paid enough or appreciated enough, but we still do it because we love it.
I would love for families, especially those in wealthier towns, to see the lives of teachers: like, show them a slideshow of their home lives...where we live, what we drive, how we make it work...