I have a comment on this post and the missing year post...
I just go with the guide that works for where the kids are at. This would have me end after 7th grade also. But, things keep getting harder academically each year for my ds. So, I really appreciate the extra year's room to slow down and not shove him through a guide. Last year in Bigger, I should have slowed at the beginning of the year because it was a hard adjustment for him. But, I shoved him through too hard. He was fine by the end of 2nd grade, but the beginning was ugly. This year, God gave me a do-over. I prayerfully decided over the summer that even if Preparing took 2 years, I'd rather have him enjoy school. Now we do as many of the boxes as we can in a day, but quit at 1:00. That's 4 hours of school and he's exhausted learning the more challenging skills. So, everyday we do math and cursive and work on the verses to memorize (he needs longer) no matter what. Then, we do what we can and feel at peace with it. God has really blessed our decision and given us great relationship and discussions. Julie had given me the encouragement to start out slower with it being a tougher year for him and I appreciate her wisdom in that. I think I just needed someone to tell me that was OK. And, if I finish in the middle of a school year, I'm just going to be flexible enough for that too. God seems to be growing me through homeschooling too!
So, after my wordy rambling, I would advise you to just keep moving because I bet you'll hit a harder time in your children's schooling where you'll want the room to slow down. God bless your planning and desire to look down the road.