Amidon is great for ECE. Data seem to imply kids who score well on 3rd grade standardized testing are not at the school for 5th grade testing, so there seems to be reasons some families don’t stay for upper grades. Data also seems to suggest some IB kids without sibling preference did not get into PK last few years so yes, you do need backup plans. Thomson, Capitol Hill Montessori (you’ll want to make sure the philosophy and potential hiccups transferring from Montessori to non Montessori later is worth it), SWS, Tyler and Peabody are what I would do, in that order (mostly due to commute - I will die on the hill that ECE and most DCPS/DC charters are not markedly different). Add Appletree at the end.

You won’t get into PK OOB at Van Ness (which I do not think is any different than Amidon) or Brent (and probably not SWS or Tyler to be honest but I’m not currently looking at the historical waitlist data site, just going by memory that PK seats seemed to be going to sibling preference (SWS) and inbounds/sibling (Tyler) not OOB).

Good luck!

OP - no one has mentioned your "going private" comment yet. Our older child is in private for K, younger one is in Prek3 at DCPS on the Hill. We ended up going private and commute to a school in Georgetown which is a pain from the Hill but when we looked at long term options on the Hill, we weren't happy with them. If you're serious about going private, I would start looking now. There are very few privates in SW/CH - you're basically looking at St. Peter's (Catholic, hard to get into even as a parishioner because it's so small) and Capitol Hill Day (which is a progressive school). We are more traditional in our educational philosophy and are not parishioners at St. Peter's so neither were a good fit.

Our kids did / are doing prek at our inbound elementary which was great for prek...but if you looked at the older grades, kids peeled off every year for charters and better middle school and high school paths. I wish someone had told me a few years ago about that, would have changed where we lived in DC. The Hill is great for lots of reasons but the schools leave a lot to be desired.