I believe you would be well served with 12" spaced forms.
There is nothing more "tedious" than figuring out your 18" spaced forms are off a little bit and you have hollows and bumps in the boat.
2 years later I'm still finding them.
Additionally 18" and 3/16" strips allows them to bend much more while you are sanding causing the fairing job to be difficult or even poor.

I'm not going to build one again without 1/4" strips and 12" spacing.

There are better builders I am sure who will think I am excessive. So be it.
Actually I have never seen their boats in person so I don't know what the actual comparison would be.
I just want mine better.