[marginalia_nu]

Seems a bit like StretchText.

In general parentheses in text should arguably be avoided in text. They almost always make the text harder to read. You can generally re-arrange the text to be clearer, sometimes by simply removing the parenthesis, in others by moving the aside to its own paragraph.

[devidw]

Thanks noting StretchTex. Never heard about it before. Indeed, it shares the same motivation: Allowing users to decide what and in which detail they want to read at.

I would love to see your conclusion about the usage of parentheses respected by authors more often, it makes content so much more accessible and would make a solution like this obsolete.