with BMax's history of breaking existing code and existing mods and requiring many mods to be recompiled for each new version of BMax, it makes much more sense to make it available as a DLL. Easier to use, less hassle and less compatibility problems to worry about.
I don't really see how. He's gotta have a honking great chunk of BMax code to have the OO design anyway. Making it a pure module would mean more imported c code being compiled in GCC, not any more BMX code.