I like what you are trying to achieve, but it doesn’t fit into the vision that the loop operator was based on. If you look at the doc for the loop operator, it says: “Later actions and operators in the workflow can begin before the loop step has finished iterating over all objects in the list. However, the workflow itself can’t end until the loop has finished executing. For this reason, adding additional steps outside of the loop between the Loop operator and the end step is not recommended.“
Based on that alone, it sounds like your workflow could potentially send off all the forms, then process the remaining steps in the workflow, and then just sit and wait for the forms to be submitted/cancelled before ending.
For your use case, you could build something outside of ISC (UI dev kit or otherwise), or put a limit on how many APs can be added in a given request. If you place a limit, then instead of a loop you can explicitly call the forms and read the result. The logic will be uglier, but it would work. If someone wanted 50 APs and you limit the form to 5, they would have to make 10 separate requests.