It's not really a direct answer, but another proposal :-(
Your Quartz jobs can be paused, canceled and so on, let's call it "managed". I guess you will create some UI to manage them.
Do you realize that you your other jobs ("on demand") will not benefit from the same functionalities, unless you implement it of course? Did you consider making everything a quartz job (even if it starts immediatly), to get a uniform code?
