Yeah I kind of figured: even with all my strongest stations at 100, I could still increase amplification quite a bit before I saw any signs of overload. So the HDHR doesn't really tell you how close you are to the point of overload. The best I could do was set my amplification so that a few strong stations were slightly under 100, and as long as the weaker stations were still OK I figured I was fine.
I just don't recall ever seeing a cell tower signal that strong before, and I figure some folks are even closer to a tower than I am, so they might have a problem (especially if they're in a fringe TV reception area).
Strangely, that strong cell tower signal was on for just about exactly 24 hours, then today it switched off again. So it must have been a test. But I suppose eventually it will switch back on permanently.