I had a problem on that build, since the very beginning.
My stringers slipped one side, when the boat was bottom up. I've checked the alignment several times, so I don't know how this happened.
Anyway, the tip of the stringer on starboard is not touching the chine panel, there is a 1/2 inch distance, and of course, on port side it goes out by the same distance.
I had to trim the now unmatching frames, in order to fit it straight.
That worked well, untill I put the hull panels.
They are ok, but the starboard panel didn't bent like the other, it has a slightly lower camber. It is only observed at the gunwales.
So, I built an offset rubrail, thicker in the middle, to compensate that, and after dry fitting the decks it looks fine.
I hope that a 1/2 misalignement on a 20 ft boat is not such a catastrophic mistake, because I can't undo anything.
I'm kind of sad, because I did try my best, and I wasn't in a hurry, no deadline, so I did everything by the book, except for that.
But I have to go on, it is not a structure issue or something like that.
The only thing is that now I can't rely on the plans. I will cut the pieces by the plan, and adjust them to fit, I think is the best thing to do.