Gunwale replacement

When replacing gunwales on a Kevlar or fiberglass canoe is it better to have the Kerf (or notch) on the Inwale or the Outwale? My Mad River Guide (original gunwales) has the kerf on the inwale as did my Allagash canoe. I’ve also seen the kerf on the outwale of some canoes. Which is better? If I had slotted gunwale I would slot the inwale and kerf the outwale, but these are not slotted. All input appreciated. Thanks, Jim

I would rabbet the outwale
As you pointed out, if you have scuppered (slotted) inwales and want complete coverage of the top of the hull, the only choice is the outwale. But even though some makers (Mad River most notably) chose to rabbet the inwales, I would rabbet the outwales.

If you have seats suspended from and thwarts attached to the inwales with #10 stainless machine screws (as many canoes do) you would like to preserve the full width of the inwale so that the holes for the screws weaken the wood to the least possible extent.

Is it worth it to bother with a kerf?
To me, lack of a kerf means easier future maintenance.

kerf on outwales
I never thought about the kerf making the inwale narrower and therefore weaker. I’ll take your advise in place the kerf on the outwales. Thanks