This is just an idea for Opus 13 or beyond.
It would be good and future proof for Opus scripting to have the official Lua scripting support built-in.
I know it's possible to add anything via ActiveX, but it would be good to have one standard Opus scripting language that just works and doesn't rely on Microsoft's good will.
Why Lua? Because it's extremely small (memory wise), fast and very easy to integrate in C++. It's also very simple to program in (like jscript and vbscript).
Side note: Python would be preferable, but Python is large and Lua might be easier to integrate.
EDIT: Full JavaScript (ES6) would be even more preferable (let, const, lambdas etc.).