How about having a new tab in the configuration dialog of all nodes as “Schedule execution” or something similar which allows users to:
Schedule the node execution based on time. (maybe a Wait… node feature in all nodes)
Schedule the node execution based on the status of other nodes. If this method of scheduling is selected, then the user can add one or more nodes (node IDs) to a list to make the current node be executed when the nodes in the list are executed.
Please vote if you would like to see this in KNIME AP.