I write my Wherigo Cartridges in LUA language because programming comes more convenient to me than creating workflows with a proprietary tool.
I still use Urwigo for compiling and for importing media files.
In my opinion writing the Cartridge in LUA has several advantages:
You have your program in an independent language. If for some reason Urwigo would no longer be supported or if you want to migrate to another WIG compiler, I imagine it makes migration much easier.
With programming you can write logic and functions which are re-usable. For example one function which is executed on every zone entry.
You can write things which are not possible without programming.
It is much harder to analyze the Cartridge (for those who only need GC-points but dont want to play the game). Or in other words: there are many possibilities to obfuscate coordinates.
I publish my Wherigo sources on sourceforge. Why? Because this is the way I do it. Feel free to browse the code and re-use it for own purposes.
Be aware that my sources are published under the GPLv3 license and respect the terms of this license.