If I recall correctly, the special feature of the Nocon timer is that it offered factorial exposure times rather than simply linear seconds. I've got his book (Photographic Printing by Gene Nocon), and the timer is supposed to make it easier to adjust tonal adjustments from print to print, and I suppose if you're clever, it could help with dodging. As I understand it, it's simply a timer but with a facility to adjust the exposure in factorial half-stops etc. rather than by simply adding an extra 5 seconds, or whatever. That's why the keyboard has +1/2 and -1/2 labelled buttons etc.
I don't know the De Vere 504 so can't comment on its suitability with this timer, but if it uses a standard halogen or tungsten bulb, I can't see any problem.