Pardon my ignorance....! I'm never in touch with TV programs.... what's CEW?
As far as veneer goes I think size depends on the species and what you are using it for.
For example is it for balancing the backs of boards or do you want it as the face of the piece and to exhibit the grain patterns? If it’s for balancing unseen backs then the size and visual quality is unimportant.
Large sheets tend to be roll cut from a log, rather like carpet on a roll and don't have the grain figure you would get with stock that is quarter cut. This is important with Oak, for example and other timbers that rely on medullary rays or the chataillance you get from good mahogany, for their effect.
I have noticed that most commercial faced boards have an ‘A’ side and a ‘B’ side, the better grain pattern being on the ‘A’ side. Sometimes with the ‘A’ side it is pot luck as far as grain pattern goes. Usually the ‘B’ side is roll cut and is an almost continuous sheet, sometimes the other side is quarter cut, sometimes not.
Most figured veneers are cut radially from the log, mostly quarter sawn (though not exclusively), so will only be as wide as the board it came from, minus the sapwood.
Hope this helps