-Dwebgl and other flags?

No, unfortunately this isn’t really documented.

Lime has -Dwebgl, -Dcanvas, -Dcairo and -Ddom to force specific renderer types. WebGL is the default, canvas is the default fallback if WebGL fails for HTML5. GL is the default on desktop and mobile, Cairo is the fallback if it is not vailable.

-Ddom is the only method that is available only by request right now