I also brute-forced this. I figured there's a bit optimization to be done if you "draw a line" to the next obstacle instead of going step by step, and also maybe exclude some areas, but in the end I just set an exit value to break if the number of steps exceeded a certain value and say that was a loop. Took almost 20m but a star is a star.

update I only added obstructions in the original path, which cut the time down to 5 minutes or so.