Do the levels the indicator hides still act? Yes.
Hidden support and resistance lines hold at essentially the same rate as the ones the app draws (70.6% vs. 70.4%).
Support and resistance lines only – trendlines only mark a single bar as hidden (too noisy to compare), and the grid, golden MA, and volume profile families never hide any lines.
Hold rate
Out of every 100 real tests, how many times the level held. The line marks 50.
The app doesn't draw every line it computes. Some support and resistance lines get hidden on the chart because a bigger line sits right on top of them. We asked: do those hidden lines still act like real levels, or are they just noise the app was right to hide?
For support and resistance, they still act. Hidden lines hold (reject a test) 70.6% of the time, versus 70.4% for the lines that are actually drawn – a difference of two-tenths of a point, which is nothing. Whether a line gets shown on the chart is a display choice about clutter, not a sign that the market has stopped respecting it. A suppressed line is just as live as the one drawn over it.
We could not run this same comparison cleanly for trendlines. A trendline only gets marked "hidden" for a single bar – the bar where it jumps to a new pivot – which is a different, much smaller, and much messier situation than a support/resistance line being suppressed for a stretch of time. That single-bar group has far more untested breaks than tested ones, almost certainly because the line's value itself just jumped, not because of anything about visibility. We are stating this plainly rather than reporting a trendline number that would be misleading: this entry's finding covers support and resistance only.
Two other families – the golden grid and the volume profile – never hide anything at all, so there was no comparison to make for them either.