Chris Melling should know the answer if a different vault plate effects the energy transfer. After playing with a standard Revo (not sure but my guess 12,4) I've noticed him playing with a different Revo with a white vault plate once custom Revos were introduced. The last time I've watched him playing he played with a Revo which looked like a standard one. If he switched back to his old one he might have his reasons for that but that is just my observation and guess.
I can share my experience with vault plate out of different materials.
Being curious I've bought a c.f. blank from a supplier I know to finish the shaft on my own. So as I've liked the look alike Mezz Ignite with white vault plate and brown fiber pad firstly I made the vault plate using lighter white material which worked great for the ferrules on the wooden shafts. So I've made similar combo white vault plate & fiber pad on top.
Once the shaft was ready I was eager to find out how it hits and was dissapointed because I did not like the hit at all. So as the easiest way to change the hit was to change the vault plate to a harder material I've made it out of black fiber I used for break or jumps cues and for visual thing just put a thin pad out of aegis on top. This operation changed the hit very much and the shaft played much better.
So long story short material matters a lot and for that kind of vault plate/construction the harder material is better (imo). My guess Mezz uses aegis for their white vault plate. At least it looks very similar to it.
The chances you get the answers from somebody who has the experience you're asking are not very high so you may have not so many alternatives but to have your own experience.
It is a silly thing they at Predator could not answer what material they use for their white vault plates
If you decide to pull the trigger I wish you're really happy with what you get,
Sergey.