Personalization to populate Promised Ship Date when Promised Delivery Date is populated

Summary:

We have Buyer Managed Transportation enabled at the Procurement BU level and all our POs have the BMT flag enabled.

The customer wants to be able to enter either of the Promised Delivery date/Promised Ship Date on the Purchase Order since different suppliers provide different dates.

Since, whenever Promised Delivery date is entered, Supply Planning does not consider that date (for BMT flag POs, Supply Planning planning follows Promised Ship Date > Requested Ship Date), we are trying to find a way to update the Promised Ship Date whenever the Promised Delivery Date is populated.

Is there any way to achieve either one of the following when Promised Delivery Date updated -