I am going to answer some questions you didn't ask (and one you did). Apologies in advance.

For reference, I was in a gifted program and went to a gifted magnet high school. I have been fascinated by gifted ed since then, and I think much of it is still lacking (on several dimensions).

1. I think the best thing that can be done is keep the kids' ACE scores as low as possible, ideally at a 0 or 1 (that 1 being divorce). The ACE scores you mentioned sent a shiver down my spine. I'm sorry that this has happened to you and your family -- I am glad to see that you are able to mention it.

2. You can stop taking IQ tests unless you just enjoy taking them. The last time I did a deep dive into the IQ testing scene (about 20 years ago), there were not any psychometrically validated tests for adults that could measure over about 150 (that's around the 99.9% level). Also, if you continue taking them and happen to score lower than usual, don't think that you are losing it -- there is probably some external factor (e.g., a bad night's sleep, and particularly tough workout, etc.) that probably negatively impacted your score.

3. The best thing you can teach high-IQ kids, imho, is EQ-related stuff. One of the biggest challenges for many folks at my high school (often the smartest) was interacting with other people, especially people who are not near their level of intelligence. The folks who were smart and had (I am guessing) high EQ have done very well in life in a variety of ways. The folks with lower EQ... not so much.

4. As for education, I would try to introduce them to a wide variety of self-study tracks, ideally ones that can go very deep into a topic. One of the cool things about my high school was (like another poster said) that we had a lot of free and unstructured time. Furthermore, we could self-study a wide range of topics if we could find a sponsor (and there was always a sponsor if you could do the work). Looking back at my time in high school, my one wish is that our sponsors would have encouraged us to look more at graduate level texts. Looking back at my own education, most of the texts that I would consider "good" did not start popping up until upper level undergrad courses and in graduate school. Most, if not all, of the texts were not above the comprehension level of my high school peers, and I think we would have been better off had we been fast-tracked that direction. I would try to avoid any sort of classes that have a lot of repetitive busy work (this is a recipe for disaster with most gifted kids).

4a. One challenge with gifted kids is that they do a lot of things well, and the limiting factor is often times just time. I would encourage you to introduce your kids to a wide range of fields, but I also encourage you to give them some heuristics early on that may help them decide what to focus on. Three heuristics I give to younger people who are interested: 1. choose a field that has people you like to spend time with, 2. choose a field that has work in an area you want to live (e.g., don't choose finance if you are an ambitious American who doesn't want to live in NYC), and 3. choose a field that has interesting and hard problems to work on (and optionally if you care about money, that people want to have solved). These are not perfect heuristics, and there are probably better ones, but these three cut out a lot of fields very quickly.

I hope this helps.