I think it would be helpful if the UI for aborting jobs in Terra was more prominent. I find I have to terminate jobs pretty often, especially when testing new workflows.
In FireCloud, the job status page has a massive red "Abort Job" button. In Terra, this is replaced by a tiny green crossed circle that's only on the job manager page. I haven't found a way to delete a job from the individual job status page. It also took me a little while to realize the green cross was the abort button - it'd be nice if it was larger and red like the old symbol, or said "terminate," or something else to indicate what it does and make it easier to find.