Have you tried creating multiple instances of the same light (in the Instances panel of the Lights tab)? This would allow you to create multiple identical light sources, with properties like strength or size changed for all of them at once.
There is also a light naming convention which allows you to import lights from a 3D file (eg. FBX, DAE) as instances of a single Shapespark light: Any way to create lights externally (withhout sketchup) - #10 by wojtek