John,
That is fine description.
Not what I have seen - I have not attempted to get the assigned ID back from an INSERT, from within a service. But I suspect it is possible. I do not have the product or documentation immediately at hand.
If the original INSERT has one of a combination of columns that are unique, perhaps a second statement, a SELECT, could retrieve the ID without worrying about multiple users (unless the row might be updated or deleted before the SELECT occurs).
Without the docs, here is the path I would take. Go through the steps to set up a SELECT. Note the handling of output from the statement, the words in the UI. Then do the INSERT development steps again, and look for those words. If you don’t see, it may be that handling output/results from non-SELECT statements is not supported.
Sorry I don’t have better to offer at the moment.
Mark Thomsen