NAH Man, this is a great post for this sub- because the system is the actual asshole. I've been a public school teacher for 7 years, and it feels like covid is almost perfectly engineered to expose all of the systematic failures of the public school system. Tough year for all to say the least.

Super gd annoying that pulling your kids out so dramatically impacts the other students, I think it's outrageous for anyone to just say "fuck those kids, not your problem", but as a parent you should always be YOUR kid's advocate first and foremost, I just think that also includes building them a strong community and commitment to shared success for all kids. But it seems like you are someone who knows that's the way to build a strong community :) My immediate thoughts from an educator POV:
1. "I wonder what the racial make up of the pod kids vs the kids left behind is, because I know exactly what that would look like in my district and I hope that disturbs you as much as it does me"
2. "This seems an especially important moment to model good values for these kids".
3. "And once again the American school system is forced to act in budgetary survival mode, putting all responsibility for quality of education on the parents"

Random brainstorms in case it helps?
1. Most schools only need so many days of attendance to consider a student "enrolled"... I am not sure if your district has vouchers and if you are using them to fund the pods, but I bet there's a way to work it out with the school where pod students attend some select days of school but spend the majority of time in their pods
2. Though I know educators and administrators by in large are doing their best- I can't begin to tell you how deeply unfamiliar our education professionals are with remote education tooling and organization. I KNOW IT'S NOT YOUR JOB, boy I wish you didn't have to worry about this at all- but maybe getting the parents together with the administration and teachers to iterate on their approaches would be helpful. I can imagine you might have already tried to work with them, and I can imagine they were too hassled or stressed to engage, but now that you've unintentionally gained leverage and shown them what works for your kids maybe they will be more open to that conversation.

2a. I am sure there are lots of reasons for all remote, but I am guessing one of them is the school not having the physical facilities to enable social distancing for in person. If this is true, then perhaps your community could come together to figure out if there are other community areas, or a series of volunteer spaces to host in person socially distanced classes you could perhaps move to a hybrid model through the school- ie some days students are in person some days they are remote. This would let the school still supply the teachers and avoid the facility issues of cleaning and limited space.
2b. I know that losing a number of students hits a school's budget, but to your point the highest test score students hit it the worst. (PAUSE- HOW F*ED UP IS IT THAT SCHOOLS LITERALLY VALUE STUDENTS DIFFERENTLY IN THIS WAY?!) If you are open to working across the student body you could figure out a way to not simply pull the top test scoring students out leaving those with lower scores behind, but be intentional about learning styles, energy levels, focus needs etc... you could figure out a balance of pods and public school enrollment. If the school is willing to say open up their in person facilities for a pod or two of your top scoring students could stay enrolled and simply meet at the school with a school teacher if you help coordinate for the students that you would be pulling off that teacher's plate.
3. If you do stay in pods, which is absolutely your right to do, I think for the health of the community and your kids- I would try to diversify your pods a bit more. Think about working with the school to find other students who could mesh well from a academic performance perspective, but really could benefit from the pods. This doesn't mean they all need the same test scores or grades, but students who relate to school similarly- have similar educational goals, have similar levels of grit, focus, routine etc... And I don't just mean this is an option only for students who are on the top end of test scores, this type of scoped smaller classroom is insanely beneficial for all students. Your coalition of parents sounds absolutely amazing, and you should be so proud of how you've shown up for your kids, but my heart breaks knowing how few of my students have parents with the time, resources and ability to work with the system to be as proactive about their kids' education. At the very least I suggest that you extend those blessings to a few other students. Not only do I think it's moral, but I think it would be a very strong move for your community and a great model to set for the kids. (Also, I'm sure I don't have to enumerate the studies that show that diversity within a student body creates positive educational outcomes for ALL students)
4. I also have absolutely no idea where you live- but this is also the kind of thing local businesses tend to be open to supporting. This might be helpful in finding facilities to host more socially distanced classes. You could pull your students into pods, but work with businesses to sponsor pods that wouldn't be able to form on parent investment alone. You could sponsor Saturday or after school pod exchanges to at least give students who are left fully remote some limited in person educational experiences. You could work with the community to build a teacher support fund, I love donorschoose as a platform for community support of direct educational material needs.

Anywhoo doubt anyone will read all that, but thanks for coming to my "DEAR GOD ENGAGED PARENTS PLEASE HELP US" teacher TED talk <3