Too much reflex and you will end with more set.
The more set the slower the 'rebound' speed of the wood.
The r/d design allows the use of well reflexed outer limbs. The deflexed section lowering overall strain and allowing a lower string angle at full draw. This lower string angle means you are bending a thicker piece of wood and thus storing more energy. The design when executed well speaks for itself. Very low handshock, stable and fast.
What's not to like other than being a wee bit tricky to tiller haha
I think you have done a good job on this one. The trick when figuring out a 'new tiller' is to pay a lot of attention to exactly where the set shows up during tillering. You should always follow the bowyers bible 'mantra' of no set inner limb, a little mid limb and the rest out to the tips. The wood will always tell you how it should be tillered, it hard to hear sometimes though!
As for multiple lams - yes that is definitely the way to go to achieve 'accurate to your form' glue-ups. Bending too thick ipe belly lams leads to many problems. One is the different profile in your limbs. For a r/d bow I would always go with a tri lam.