Instead of going for new ideas of having more materia slots, I say we should just get back to the original proposition of closing the gap between NQ and HQ. I mean, look at this:

26 Craftsmanship difference and 8 Control???!!! That's just ridiculously much. If you NQ-ed it at 80% HQ rate, it's functionally useless since it's no difference from an HQ i150.
What if, the difference in Craft is like 12 and difference in Control like 4. Then at least NQ still has a chance to function. Right now NQ is nothing more than a pure glamor item.