Hi,
SAP responded to my ticket and gave me access to the pilot note 1510700. I have implemented it in our development environment without issue, and now I have the ability to delete a MAA line using BAPI_PR_CHANGE.
In order to delete a line, I have to change the percentage distribution for the remaining lines, so that they total 100%. Then, I have to set the deletion indicator for the MAA item to be removed in PRACCOUNT and PRACCOUNTX. I do not have to adjust the percentage of the line being removed.
Thanks.