Nick,
Normally, the macros will not have the issues you are seeing. The reason why you are seeing them now is that we changed LUA versions between build 1767 and 1817 and there are incompatibilities with the compiled scripts between the versions. Normally, the installer will install the macros with mcc files that work and there will be no issues.
For the macros, Mach uses the mcc files. The mcs files are just a way of getting to the mcc files that us humans can read and modify. Mach can run without ANY mcs files if the mcc files are compiled and correct.
Changing LUA versions is not something we will do once we release. We just made a push to get to the latest code base for everything we use so that we don't feel the need to do it at a later date after release. In the future, a normal user should never see this.
Build 1817 has a whole host of changes including a move to wxWidgets 3.0, LUA 5.2, and we went from using the static CRT to the dynamic CRT. Hence the massive difference in build numbers. I also did a wholesale change on the API (I'm so glad I haven't re-written the API docs again!).
We have one more big change to do before release which is the installation location (feature request and docs not withstanding). We are planning to conform to MS program installation locations so that Mach will be installed in the "Program Files" for system wide operation (requiring Admin privs) or it can also be installed in a user folder without admin privs.
Steve