USEREXIT_CHECK_XVBEP_FOR_DELET USING US_EXIT

Can anyone tell me under what conditions this user exit in MV45AFZB gets hit? I would expect it to get hit when a line is being deleted from VBEP, but it does not seem to be hitting it.

My requirement is to find a place to update a user field in vbap after a change to the order triggers a return to credit hold. SAVE DOCUMENT PREPARE gets hit before the credit check so I cannot do it there and SAVE DOCUMENT is too late since the tables have already been updated.

When we have a single entry in VBEP that has a confirmed quantity, a return to credit causes it to hit USEREXIT_CHECK_VBEP, but if we have two lines in VBEP where the confirmed quantity is on the second line and the it is getting deleted, there is no change to the first line and it is not hitting this exit or the subject exit.

Any assist is greatly appreciated.

KJB