i think its a great question and i thought a lot about it.

on my latest build i just decided i didn't want to bulid up a traditional strip build cockpit and paid CLC a bit of extra money to sell me the  risers and coaming of a petrel play stitch and glue and used it in my strip build petrel play.....which normally would have required the risers and coaming to be made out of almost 100 individual bits of wood.

there are folks who do bulid out there risers and coaming with one piece using carbon fibre over cut foam that they place around the cockpit opening.  so that's one approach. 

with respect to your idea, i would give it a go and see what happens.  i think the challenge from my perspective would be sorting out how start with the right blank that is shaped correctly with respect to the opening and the deck countour.  and then after that, how to engage a router properly with the piece.   but give it a try....the worst is you learn something that you can share and have to change tactics.  the best is it works and you share how you did it.

on making it look nice...i don't think you lose anything.   i think it just depends what look you are trying to create and does it work.   no shortage of nice comments on my petrel....nobody has said yet, "love it but you messed up the coaming".

h

As Howard says, what you propose is no doubt possible.

My approach is to cut my own ply spaces and coaming lip from Sapelle.  I like how the Sapelle contrasts with the strip deck and it is a lot less work then gluing up strip risers.

You could adapt this method from our Redfish King stripper build...

We made a 4" or so wide glue lam of thin veneers around a cockpit shaped form.  

This joint held with masking tape is crucial for both the riser and rim.

We then used it to plan strip layout of the cockpit recess.

After deck was glassed we used it as a template to cut a matching opening.

Don't have pics of next steps but glued and filleted then used saws and routers to trim combing riser to the proper profile. Tricky bit of glassing. Used bias cut glass, not tape. Fillets helped on outside deck/combing joint. Combing rim was built up the same way on the same form as combing riser. Rim is laminated with a little extra length and the joint is kerfed in for a perfict fit around riser.

Props to Joe Greely at Redfish Kayaks for developing this method.