Don't know if you saw this article by John Harris but in any event, here it is:  http://www.clcboats.com/life-of-boats-blog/inwales_for_plywood_boats.html?jm=1

I'm sure there have been literally thousands of modifications to CLC boats and probably more than a few Passagemakers with scuppered  inwales.  The trick with any boat is careful planning for this mod, specially for the take-apart model.  I would think if you going to build that model you will want two spacers to meet at the cut line, a saw blade width apart. Then again, depending on how long the spacers are you may want one to span the cut line.  Whatever you do, lay it out first to make sure it works.

Yes, I'm planning on seriously looking into the possibility of including scuppered inwales on my Passagemaker even after reading John's excellent write-up.  It will be my second boat (Eastport Pram complete last year).  OnceI get to that step, I will make the decision.  Some of the pros are:

Already have a boat, so no pressure to build on the 2nd one.

Alreadybuilt one boat so I shouldn't be repeating any of the mistakes I made on the first one, although probably plenty more to make.

I want the passagemaker to be considerably more attractive with a few custom tweaks.  I'm planning on inlaying a compass rose and doing faux fancy teak decking on my CNC router.

   The spaced inwale kit is offered under kit options for the Passagemaker ($349)