It is standard here for gt/honors track to have Algebra in 7th and Geometry in 8th. Our local high school is hostile to kids accelerating more than this. You may want to check out how this would work with the high school that you want your child to attend.
Our middle school was willing to do an independent study version of Algebra II for DD. When we spoke to the high school which is an IB school, they said that she "wouldn't fit in the IB schedule" if she did this. It really turned me off to the school. DD still wants to be there for their music program so she is more willing to compromise than I am.
I have a friend who ended up taking her daughter to another high school for Algebra II in 8th grade. They made it work but the schedule was not ideal. The high school was on a block schedule so classes met every other day for two hours. The middle school had her scheduled for electives at those times that she attended on the days that she did not go to the high school.
I guess the message is that it can work but you need to make sure that the high school has bought into the plan.
