It isn't so much about the red deficiency of the bulb, though that's part of it; it's about the red panel clipping before the others do, which limits white level. My understanding of how you're supposed to use SMART III is that you use a color correcting filter so you don't have to drive red as hard. Since you still have some leeway with blue and green beyond that, you then raise their levels to restore color balance. That gives you the maximum white level possible without clipping. You're basically trying to max out the panels to get as much white level as possible out of them without altering the color balance. This is different from CONTRAST in the user menu, as it is a global control of all three panel gains simultaneously.
The main RGB controls for white balance are more of a midrange control, from my understanding (though their consistency depends on the gamma of each color). You should use them to balance things out around the midpoint (50IRE), then use the gains for 70IRE and the offsets for 30IRE. If none of the panels are clipping, the rest of the grayscale should line up. If you see that one particular color is not increasing equally with the others, the gamma controls for each individual color can help. You'd have to change gamma, then readjust the gain/offset controls to compensate for the change. I wish I could afford SMART III right now, 'cause this sounds like the kind of tweaking I'd really get into.
You got a CC40R? I was thinking 40 might be a bit much. I still have some room to tweak with the 20, which is why I was thinking the 30 might be better suited.
Was I anywhere close with my eyeballed settings as far as the grayscale goes? If you find a really optimal setup with the CC20R filter after you've spent some more time with it, please post the settings. I'd be interested to see if mine is fairly consistent with yours.
All in all, though... I'm not unhappy with these results. Steve Smallcombe only got a 713:1 contrast ratio out of the Z2 with a CC20R filter, so the Z3 is performing significantly better.
Something of interest from Smallcombe's site:
The key to understanding the improvement in contrast and black level with CC filters is that the black level is determined by light leaking through the LCD panels, (or internal reflections). This leakage level does NOT increase with increased panel drive levels. Now the factor of 2 attenuation of blue and green by the CC filter at IRE 0 is fully manifest on the screen leading to a factor of 2 improvement if black level and contrast.
You might think that this process might mess up the color balance at low IRE levels, but in practice it can actually help. Keeping with the LCD example for a moment, if the polarization plates for all three colors are all equally properly adjusted, one would then expect the color temperature at IRE 0 to reflect that of the source, i.e missing some red. Since the CC filter is chosen to compensate for the bulbs red shortcomings, this same CC filter can help correct the low level color temperatures as well.