Your post has interesting timing for me because a couple of years ago, I had my heart set on sending my DD to a Quaker school in our previous state of residence but don't have the option here. It's been on my mind the last couple of days because my DD's interest in school is sinking fast (4 more days until vacation after today!) and I thought "if she could only have a school like that instead...")
It's very interesting to read about your experience. I guess I should stop sulking now!
Do you belong and participate in the Friends community at large or was the involvement strictly for the school? I guess if your son is on board with the learning at home and can keep in touch with his former school friends through other things like scouts and sports that would ease the transition, assuming they handle it nicely. Then you'll probably be joining a local or regional home schooling group and will try activities with them. It'll transition over and if he is excited about all the learning he can be doing with his time he'll just transition over to this new phase of his life.
When I took my DD out of K ˝ way through the year she was only 5 and was so happy and relieved to get out of the toxic environment. But 5th grade is so different because they’ve bonded for a longer time with their age peers, but I would think your son would like to have a say in putting everything together.
I possibly have a similar situation on the horizon with taking my DD out of the public school and probably just home schooling until the middle school transition where I think some private school options could be appropriate, and we should know more about what she needs from a possible 2E perspective by then as well. I would be leery of popping her out of this public school and into a private without some "unschooling" in between to recover and catch up.
I think we might give them one more "semester", fall of 4th grade, after trying at the end of this year to get some more robust accommodations in place, and if it doesn't work by Dec., and she's as miserable as she's getting to be as this year moves along, we'll take her out. This would be very odd for her because the neighborhood is very geared toward this school (it's all about the rankings). But we've met some other people lately that have taken their HG+ kids out of even the high ranking schools (or possibly, because they are high ranking they just focus far to much on the state assessments) and because we're meeting these kids out in the community and she has such great conversations with them, she might feel less loney with this community of people than she does in school.
This is our first year with the state assessment experience and I'm getting a very strong appreciation of the whole "teaching to the tests" debate. I could appreciate it in theory until now, but to see them learn absolutely nothing but the bare minimum that will be on the assessments and go over it and over it and over it...I just can't believe it!! School rankings by scores on testing have taken on a whole new dimension for me.
I'm currently reading "The Well-Trained Mind" and even if you're not doing the Classical Homeschooling it's a good book to read and there are sections about starting half-way through the child's schooling experience, and the things you have to deal with that are different than just starting from the beginning (never sending a child to school at all).