In my case it was a lot more of headbanging, the traverse function i wrote for part a was way to slow, since JQ isn't happy with loop-heavy assignments (if not buried within C-implemented builtins). Part a completed in ~2seconds, which was never going to do (in hindsight it would have taken me less time to simply let it run slowly), I had to optimize it so that the beams don't step one square at a time, but shoot straight to any obstacle.

It took me waaaay too long to troubleshoot it into something that actually worked. I'm sure there's a compact implementation out there, but my part b ended up looking very meaty (and still took ~30s to run): https://github.com/zogwarg/advent-of-code/blob/main/2023/jq/16-b.jq