The reality is that you get multiple bites at the apple. You challenge at trial and in an IPR. Lose both, challenge with an EPR and appeal the trial. IPRs were initially created to simplify trial and cost, but once the estoppel provisions were determined not to have much teeth, it just became something you did because there was no downside.
Regarding law school, I would point out that law grad salaries are bi-modal. If you get in big law, you would start at $210k, if not you will start at a lot less. Presumably, with your background, your easiest pathway to big law is patent litigation, but I would say there is still a lot bias favoring EE degrees over CS, but less so than in the past (as I recall from interviewing a long time ago that was true, but at my firm, I think its less of issue, but your experience may vary).
Law school is expensive and I don't think there is a cheap option in the bay area (even the state school is expensive but in other locations, it can be cheaper), but they do give out scholarships.
I wouldn't choose law school unless you think you could do well in the actual legal career environment. I don't know what you mean by "good contacts for law school," but if that means you know people in the field, I would suggest talking to them about it. Get as much information you can get.
Any worries that law is not going to be a viable career with AI seems farfetched by me, particularly in litigation.
Key thing, when you quit, don't burn bridges. I took a year off, did some traveling after working at my job for 8 years. At the end of the year, I applied to a few jobs, but my old boss contacted me to rehire me. I went back as if I never left. I am in a different field, so you experience may vary, but if you are in a good team, your old boss is likely to rehire you instead of investing in someone they don't know and have to train.