Operationally, I've noticed that templates don't seem to be getting through the jobs queue, sometimes for days.
About 11 hours ago, I changed a template with roughly 700 invocations, and it has only had 17 or so entries refreshed (showing up in new categories).
A couple of weeks ago, I changed a pretty common template {{Cent}} with several thousand invocations, and it hadn't finished updating after a weekend! In that case, I ended up commenting out 4 years worth of old uses in discussion archives, and null editing the remaining dozen or so.... Hopefully, that made it better for the future.
Does any edit clear the entry from the jobs queue? There'd be no need for it to be refreshed anymore.
Does multiple edits to a template continue the old entries, or replace them with newer entries, or leave multiple sets of entries?
I'm assuming the queue is FIFO, so leaving older entries would be ideal, and multiple sets would be bad.