Being out of round isn't a problem provided it isn't excessive and considering just how many more ply shells are out there compared to staves, this........."
I've seen several ply shells go out of round I've yet to see a stave go out of round".........is not surprising

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Because of the nature of it's construction and the usual thickness, a stave (or segmented shell) should be quite stable. If they have a weakness, it is that if dropped, they may split along either a glue joint or one of the staves. Ply shells are usually cross laminated and this give them an inherent strength and durability that can't be built into other timber shell types. Steam bent, stave, segment and solid one piece shells are all "machined" so any imperfections evident in their raw state will usually be removed by the "machining" process.