That was the thought, I guess.That's an interesting problem, but don't you think that a manufacturer would think the simple H shape [without channel] would be a brilliant way to align both wobbly halves of the kayak when trying to align in-or-out when assembling . . .
'Quick and cheap assembly method used' isn't something I look for when buying a kayak!
I was told that Eddyline -who used H-channel a lot - were known as 'Eddyleak kayak' for years.
I wouldn't buy an H-channel kayak.