With SSIS, you can invoke user precedence contraint(s) to where you will not run any downstream flows until one or more flows complete. A simple connector should allow you to do this. Right now, I have my workflow(s) in containers, and have to disable / enable different workflows, which can be time consuming. Below is a better definition:
Precedence constraints link executables, containers, and tasks in packages in a control flow, and specify conditions that determine whether executables run. An executable can be a For Loop, Foreach Loop, or Sequence container; a task; or an event handler. Event handlers also use precedence constraints to link their executables into a control flow.