god, that sounds like alot of work, man!i
i have been copying your buildalong all week, and i now have 4 r/d blanks with the belly lams glued on...all just waiting to go...I was coming in under the 50# mark with pyramid style bows, so these ones all are wide-ish out to midlimb or so...actually, the taper begins where the recurve begins...
but i didn't pre-tiller any of them. I glued the backing and core into shape, then shaped and attached a riser, then shaped the fades and lam'd on the bellies...the most i did was to cut the basic shape out of them; you can still see the lines on the back...all the work of tillering is still ahead of me...
I look forward to seeing how the bamboo works out for you as a belly...why not try it a couple ways at once and compare the results?