Should labels be masked by default or always?

Ideas
1

See this question about masking label so that they have an opaque background and show up better on a graph.

Assuming we have ironed out the technical challenges for such labels, the next question is how should we support adding an opague background to labels. Should there be an attribute like masked that could be true or false? If so, what should the default be?

Or, as mentioned in the developer discussion around creating this masking, should that even be an option or should we just always give labels an opaque background?

2

Just as a first thought: Draggable labels masked by default, fixed ones opt-in masking?

There’s plenty of times where I haven’t thought labels needed anything more. When labeling a graph with y=f(x) for instance, or labeling a fixed point A or B, masking seems like it would be overkill and look weird. But for draggable labels, masking seems like it should be the default.