I respect your stance (although I disagree strongly) but you might consider something other than Sile, as Chapter 6 of Sile's manual is called 'SILE Macros and Commands'. Also from reading about D, his strongest objection to using macros is that they do not respect the scope. This is probably the main source of macros' strength as code generators. Again, I respect your aversion to macros, I am not sure I understand the reasons, though.
The SILE approach for macro is very limited and sane. I think that's purposely to make sure that it's simple to understand, intuitive and maintain. More complex activities or programming is delegated to Lua as mentioned in the Simon's TUGboat paper:
> SILE’s \define command provides an extremely restricted macro system for implementing simple tags, but you are deliberately forced to write anything more complex in Lua. (Maxim: Programming tasks should be done in programming languages!)
