Chroma is a great tool, but best to use as a rough guideline.
For my first projector, I drove myself crazy trying to plan configurations based on what Chroma was telling me so I could get that dot to hit the white spot dead-center on the graph. In the end, to get up and running and stop wasting time and money, the config I chose was something like .7/.5/1.25, the red being 640 and the blue being a combination of 473 and 445. According to Chroma, the combined beam should have been light purple or lavender. In reality, the white balance was great, a very slightly blue-tinged white that was very bright and absolutely beautiful. The different beam sizes worked for me, not against me, and the 445's beam creates a wicked looking halo effect around the white when the beam is moving slowly or is static.
I have some upgrades in the works which will throw the numbers off more, but I doubt that the resulting balance will be altered all that much, even though Chroma says it will be very blue. Knowing what I know now that I have a working projector to look at, trying to get a perfect white balance is a waste of time. Just get that baby running, Borg. You won't be disappointed.