To be honest having a separated queue per job is really overkill. In general you can group your jobs in certain categories and create separate queues for that. For example low, medium, high or something like this email, backend, scheduled
So for having 1 job running on on queue and making it managable you have other options as well. First option is putting it in the scheduler. This way you can make it run every minute without needing a queue. You can then use the prevent overlapping feature: https://laravel.com/docs/5.8/scheduling#preventing-task-overlaps
Try to keep it simple ;)