[chrismorgan]

That’s the sort of thing where you often use another language suitable for hot reloading for such customisation or rapid-feedback alteration. As a couple of examples I’m aware of:

• The Azul GUI toolkit uses CSS for styling of its widgets, and hot-reloads stylesheets.

• The Mun programming language is designed for the sort of niche Lua is often used, with hot-reloading scripting-like functionality to augment your Rust code. (Well, Rust is the main host language at present, anyway.)