Jigsaw cuts look like garbage IME. The boxcutter knife would work, I've done that to trim plywood before and while it takes a while the cut is sharp and precise.
All in all when I needed a one-off cut I used a box cutter knife, and when I needed a series I used a circular saw with a plywood blade. The setup is similar (needs an offset guide) but the cut is much straighter, faster, and less error prone. I think the only time I'd use a jigsaw is for making non-straight cuts like some curved artistic shape or something.