Overloading any once face with too many switchable lights is avoided if they all share the same name and are switched as one. You can have 40 individual light emiting entities or textures and it will be fine. its just when they each become distinctly alterable sources that an issue arises. Because it has to calculate each possible state for all the lights.
Eg, Lights 1 off, lights 2-26 on, lights 1 and 2 off, 3-26 on, etc.
As long as they share a name they'll be treated as one style regardless of color.
Having different appearances also causes issues when you layer to many.