More thinner plys will give less spring back. The formula is Spring back = arc height over number of plys squared. Therefor for an arc height of 3" - 3 3/8 plies will spring back 1 while 9 1/8 plys will springback 1/3. Also thinner plies take less time so soften the lignum in the wood and will take less time in the steamer. This will also give you less breakage making choice of dead straight grain selction less of a factor.. However the is more time at the bandsaw and sander or planer but it (IMO) makes for a more reliable lamination.

However the is more time at the bandsaw and sander or planer but it (IMO)
makes for a more reliable lamination.

Your suggestion still makes sense. You can control the work within the
bandsaw/planer/sander work; once it goes in the steaming box, you are at the
mercy of the clock, and how the lignin reacts to the steam. So I would always
think that anything you do to keep the process under your control is better.

I designed and built a music stand using curly redwood. I used bent
laminations, not steam bent techniques (I can't imagine trying to steam bend
such a wood), but did have one problem (two if you count the vacuum pump
failing): you have to make sure you have enough of the wood you are using when
some of the bends fail (I had just enough, and I couldn't replace any wood
lost).

However, I assume the orginal poster wanted the look of the solid bent look
with no laminations; what I questioned was the idea of doing all of them at the
same time.