@Adam I am sort of doing what you are doing with the callcontext, but also adding a step to stash the suggestion data pre processing in a UDxx table for matching up along with the fields I am passing. I use the guid hack from Jose’s post below to identify all of the newly created POs by buyer.
In the UD table keyed to the buyer and SugNum I use vendornum, partnum, duedate and quantity to find the release added post processing on POSugg.Generate and update its header.
You could also put the OrderHed pay account in the suggestion CommentText in POSugg.GetRowsPlant and then slide to the PO Header or Release from the PODetail.CommentText after the lines and releases are made.