Given that - I'm wondering what would happen if you incorporated panels but kept the forms.

Setting up forms and running stringers, then fitting and cutting panels, then removing (or keeping) the stringers and building the boat S&G style is easily done. It saves the trouble of using software or manually lofting to establish the panel shapes. Here, I'm taking about 'forms' as removable molds, not the fuselage-style forms which control the longeron (stringer) positions and are part of the finished boat.

I re-watched Nick's videos regarding building a Petrel. It appears that the thing with strips is they bend "in" nicely, but they don't like to bend "up." As a result, you end up with spaces like those triangular-shaped areas between the sheer strip and the second strip that Nick fills in with "cheater strips" - a process that seemed to take a considerable amount of time and skill to accomplish. That seems like an example of where a single "panel," cut to fit into that shape, would save quite a bit of time and effort.

Sometimes those 'troublesome' areas also involve concave or 'twisting' areas where a plywood panel would not easily fit.
Sometimes the layout of 'cheater' strips is chosen for appearance. It's also possible to lay out the strips with less 'upward bend' and then just cut along a line (sheerline, waterline, whatever) and continue stripping from that line - it can save a lot of fitting work.
(Similarly, it's possible to 'cut in' decorative curving strips in a deck instead of fitting a lot of strips to a curve...different topic..)

Taking that further - in my research on the Web, I don't see a huge number of companies producing kayak kits in the first place, and they need to market products that people are actually willing to buy. So the fact that nobody's selling a "panel over form" kit doesn't in and of itself prove that the idea wouldn't work, it could just be that there's no perceived market for such a thing.

I don't think there's a very large market for kits at all, so experimentation doesn't make sense. Also, kit manufacturers know the easiest and most reliable methods and materials to get to a usable kayak with minimum work, so that's the system they use.

It seems to me that there aren't very many home built boats being made, at all. Look at the number of 'building progress' reports here on the forum. For instance, I started a boat (longer Frej) last winter but still haven't finished it as I've been concentrating on mods and refurbishing on a few glass boats over the summer.

Here's another idea for you:
When the Broze brothers were developing some of the Mariner kayak designs, they built plywood 'inner kayaks' and then glued thick foam to the outside, which they sculpted to shape. The prototype was taken to the water/surf and paddled and tested, returned to the shop to have foam added or carved away, tested again, etc.. When they finally decided (after 5-10 rounds of prototyping) on a final shape they glassed the boat and faired it to use as the plug for the mold.
Matt Broze still has a very experimental attitude about kayaks: In a recent email he suggested changing the hull shape on a kayak with Bondo to experiment with stiffer tracking for a touring-only boat.... "easy to grind off later"