no idea; it looks like a specialty module easily used only by its author.

I ignored the module entirely realizing it's not designed for runtime calculations, with its writing to file. I didn't really try to understand it, looked like a waste of time.

It's funny though if you wanted to do it dynamically. Either !reload or read the file using xLabel after it's written if ever you figure how it works...

Something bangable with mzscript would be nicer I'd agree.

Evar arithmetic while ugly with mzscript works decently.

What difficult expressions do you need to evaluate?

I've noted that Smurth defines evars for trig functions at various values...