Greg,
14 gauge is fine, since wire size goes up as the gauge # goes down (so your 14 gauge is heavier than the specified 16 gauge). All good to go there.
If there have ever been any sort of software updates, I am not aware of them. Certainly there have been for Legacy bases and remotes. One of them was to allow you to address an ENGine type in the CAB-2 menus as a XFRM for transformer, if I recall correctly (this was a while ago - probably any system produced since the ZW-L was released would already have this software installed form the factory).
If memory serves this was to allow for the voltage from the handles to remain at the same level when you toggle the handle direction via remote, since behavior of a normal Legacy engine would halt the engine (bringing it to zero speed or neutral) when direction is pressed. For controlling the handle with the remote for control of conventional engines, this was not desirable, so they added the transformer as an engine type so that it would work the same as if you physically hit the direction button on a transformer (just a brief interrupt of the power to cycle the engine F-N-R-N-F, etc)
So you should make sure your Legacy base and remote are up to the latest if you plan to use them with the transformer, but I'm not sure I've heard of any updates for the ZW-L itself. (if there are, I don't think I've ever applied them to the ZW-Ls I bought shortly after they came out).
Enjoy the transformer!
-Dave
