Jake,
I intend to experiment making a snuffer tube this way over plastic pipe but using 1/8 inch aluminium instead of the 1/2 timber.
I have some very thin closed cell foam that will bend around the tube. So It could be made very light without going to carbon. Just sandwich layup using glass. That way it would still be F18 legal.
I'll pull the sandwich layup down with a vacuum to ensure the structure does not delaminate with time.