Wikitext for "Power Fold" - What would it take?

Indirectly but related to this thread and the if then else thread I just asked this in the developer topic Reveal according to a variable?

  • The reason is it would open up other ways to hide and reveal content
  • I have a hunch with 5.3.x features including custom widgets, hacking a wikitext symbol, or using @pmario’s Custom Wikitext an effective answer exists to the OT.