Mr Brewster....the magic acronym is not WAAS, it is FDE!
Methinks people are getting confused on what is actually required and what is candy. The requirement is FDE, the supply of that requirment need only be a blind GPS, purely to feed only the transponder.
As a navigator the 129 version 430 is still good. Did you really need to spend the money on a new 430? Did you look at All the alternatives, Mr Brewster?
This is where the argument was blurred a decade ago. Pilots were sold on the idea of a kick arse navigator. AirServices only wanted proof that your unit was excluding dud signals...they do not care what box supplies that information.