I seem to remember encountering some resistance here on this 'primitive' site about trilams and such, so I've not talked about it much, here. It's nice to see it now. I know glass bows are taboo, but if you're as particular about grinding the wood for an all wooden bow, whether a simple two lam backed bow, or a trilam, or whatever... as folks are about grinding glassbow lams, the rest of the build is a lot easier, more straightforward, and better bows result. I've ground lams and cores for all sorts of bows, and I'm set up to do it with variability and accuracy. I too grind tapers from just outside the dips to the tips for most all wooden lam bows. I don't mess around with power lams or tip wedges, I find them unnecessary. Instead, I rely on good design and shaping, good glue joints, and vary the placement and amount of taper, and wood removal, depending on how I want the limbs to act. The extensive groundwork is warranted, and should ultimately be trusted... not fought. In other words, the "let it show you what it wants to be" statement I read in the other thread is something I learned years ago and have been trying to impress on folks who are able to bring the blank to that place, and then comprehend the inherent value in it.
Like I said, it varies depending on other aspects of the design, but for a run of the mill d/r bow, I usually start closer to a .004/1" taper rate, which allows me a little something to work with while tillering.