A rabbit hole is where the real thinking is. The tangent that seems off-topic is often the thing that connects two ideas you did not realise were related. In design work this looks like walking through a use case in slow motion, checking every affordance, every edge case, every assumption made quickly in the first pass. Speed is useful for covering ground, but depth is where problems hide.
Disconnect to connect creates the mental space for this, rabbit holes need a mind that isn’t locked to the current frame.