Hmmmm, that's an interesting idea. I don't know why a VVT system wouldn't work with my cover, although a modified cover plate would probably be required. There'd have to be an adapter to bolt the VVT actuator on the FE cam, but that shouldn't be a big obstacle. Also the location of the factory FE water pump might be a problem; it might have to be spaced out, or a remote water pump used.
The cover plate is 1/8" steel plate, laser cut. I have a local steel outfit do it, so I wouldn't be able to cut one out of a different material. The reason I used this material is that I'm using an O-ring to seal the cover rather than a gasket. The gap between the two lower bolts holding the cover plate on is pretty large, and I needed the cover plate to be rigid so that it compresses the O-ring across that gap and seals properly; a less rigid material would bend up from the force of trying to compress the O-ring and lose seal. But, if you ditched the O-ring and just used RTV or a gasket to seal the cover plate, then any material could be used for the cover plate.