I had been using Google Maps but as you say it doesn't track them live and only uses the timetable. Unhelpfully it displays the bus as "departed at [timetabled departure time]" when not live tracking after the departure time which to me implies that it knows for sure that the bus has passed, when it's not tracking so it can't know that?
The 0805 passed at about 0800 with nobody on it (as mentioned with Stay Safe on the displays). The 0835 passed at about 0830 again with nobody on it and Stay Safe on the screens. I put out my hand and otherwise made it obvious I wanted it to stop, even just to ask the driver what was happening with regards to the X22, but it didn't stop.
I gave up waiting and went to Haymarket for an X38 due at 0902, I was starting to think it too wasn't going to show up but it did turn up at 0910. It didn't wait at the stop post though, it stopped well back behind a 100, and then left from there. I thought all buses in Edinburgh were supposed to pick up at the post and no further back (as in I thought it was an Edinburgh Council policy not just a Lothian Buses policy) but maybe not.