in reply to
Actively monitor space
I don't think there is or can be anything general. This is something the system accepting and scheduling the jobs has to do. If you have the source code, find the best places where a disk space check could be added and jobs either rejected or postponed. If there is a way to "pause or otherwise modify submitted jobs" it depends on the scheduler. If we don't know what do you use, we can't help.
Also keep in mind that blindly pausing all jobs might not help. There may be jobs producing a lot of data, jobs using lots of temporary space, but also jobs that aggregate data produced by other jobs and if you pause those, you are eventually going to run out of space anyway as there will be nothing that'd clean up the produced intermediary results. You need to know the scheduler and you need to know the jobs!
Enoch was right!
Enjoy the last years of Rome.