Compatibility narrows the design space.
Older nodes must continue accepting blocks under the historical rules they understand. That constraint is part of the source argument, but this lab does not judge whether a particular proposal is technically a soft fork.
Signals measure different constituencies.
Reachable node counts, miner signaling, and economic adoption are not interchangeable votes. The lowest percentage is highlighted to prevent one strong signal from hiding another weak one.
A threshold is a value judgment.
The workbench lets you choose the bar because the supplied post says adoption must be convincing without defining a percentage. No default here is protocol law, a live estimate, or a prediction.