Kelsall glass the panel before cutting the "darts", and he dont use a mould. Otherwise the idea seems pretty similar.

For a small boat I would not bother. Cost of material lost in cutting when using a proven technique is a really small percentage of the whole project. Payoff is that the technique is proven so you know what you get. If your proposed method fails, you have lost a lot of materials. You will probably also have to do some testing to verify before comitting which is also lost materials.

I think you should go for it even if I argue against. It sounds like you want to try this so you will probably not be at ease before you have tried it.