: Is there a benefit to using a "lashed" type of kayak frame such as
: Morris suggests verses a more rigid frame that Putz describes? Will the
: rigid Putz type kayak be more susceptible to catastrophic failure (the
: frame breaking in half for example)? This is in reference to quiet water
: paddling, no open ocean and no wild rivers.

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My answer is yes.
Of course, your woodwork wouldn't necessarily break in two all of a sudden, on a calm pond. But some day you may find yourself paddling in fresher waters than expected.
I don't believe in the practical value of flat water only boats.
Even if you're not a worst case scenario type of mind, give you some safety margin.
Basically, the Putz looks like a disputable design, as the flex of the lenghtwise stringers fights the flex of the smaller slant stanchions (look up post below from another builder!) when reaching maximum stretch. Even the masts on USS Missouri were built of homogenous elements of the same size
On s-o-fs, flex isn't an inconvenience, or some indifferent factor. It won't make your boat more fragile, but more lasting. Even flat water Inuit yaks had some flex.
For the same expense, why not choose the proven design, and learn about traditional kayak building?
My twopence.