The client's frequently updated. Constant re-building/re-packaging for simple tweaks is insane, and all of the program resources are stuffed in the executable. Devs don't want to add any type of plug-in system (even just for graphics). Either the tweak(s) need to justify someone building their own independent client around those tweaks, or a moddable ("official" or not, "safe" or not) client needs to be released. I can't wait for one to come out and see what happens with it!