Hmm, I am not exactly sure how to model your usecase, I just got the impression that you were abusing suspend(). From my understanding suspend() shouldn't be used in "normal" process modeling and your usecase sounded more like you wanted some sort of escalation or reminder feature. As far as I know suspend() puts the whole workflow on hold and no timer and signaling will work until you resume().
I see your point that starting a subprocess and moving the main process to a wait state is also not possible, sorry I don't have any good idea how to solve that problem right now.