Hey Vanillabear,
Not doubting your results at all but I have had the opposite experience.
I now use several thin lams for that reason. I was thinking the more glue lines helped it keep the reflex. I was also thinking that is why glass bows maintain their shape better off the form, I know the glass has a lot to do with that also.
I glue in around 4-6" (depending on the final length of the bow) of reflex and 1/4" deflex. I normally end up with about 1/2" deflex and around 3" reflex.
Just the way I do it.
Mark