You owe me one. (Not a big one, but having to listen to that hip-hop music for 90 minutes has blown my tinnitus into overdrive. I'll take an official KEXP-branded geoduck, if any are left over from the last SMDD* drive.)
Just finished a round trip from the Redwood City hills, through San Carlos east of 101, to Redwood Shores adjacent to the Bay, and then back via a different route. Your signal can now be received where I live, both in the car and on a classic FM tuner that's totally analog. (I'm listening to it right now, in mono. It's not a clean fuzz-free signal, but it is stable. In stereo it turns to trash. In the car it's now clean enough to track door-to-door, and HD does kick in fairly quickly and stay locked in most of the time. As soon as I got out of the hills, the signal was very solid, a big improvement.
If you want more granular specifics, PM me.
* "Send money, don't delay"