Just popped on here to check and I'm so glad to see your response! And glad to hear that my intuition about HISD was confirmed. We looked at ROE, but ultimately HISD's policy of having a ton of people in the GT program and telling us that our son would have to wait a year to be considered for the gifted program is problematic enough that we'll probably stick with Spring Branch even if my son doesn't get in to SBAI. We also looked at Rainard and something felt off, so despite it being the only private gifted school in the area, we declined to apply. My sense is that they focus more on 2E kids and I don't think that's the right fit for my kid at the moment.

Might DM you with questions about private middle schools--I know the obvious ones (Kincaid, St. Johns) but I'm not sure how they do for gifted kids.