Can not cancel more than one waiting queued job at a time
It appears that only one waiting queued job can be selected and cancelled at a time. There does not appear to be a way to select multiple waiting queued jobs and cancel them all from within the queue window.
This doesn't follow Windows convention or even the convention used in the local and remote windows at the top of the program that allow multiple selections.
I had queued up 100 jobs and had to cancel them one at a time!