iSupplier Portal - Promise Date with Acknowledgement functionality

Question applies to 11.5.10.2, but am curious if R12 addresses this.

In iSupplier Portal: a supplier user is Accepting an Order that does not have pre-defaulted values for Promise Date... how can we ensure that the supplier user will fill-in Promise Date?

I am running into the issue with automatically-generated Blanket Releases coming out of MRP.  Have a Need-By Date, but no Promise Date.  Would like the supplier user to populate the Promise Date (as a required field to remind them).

Looking at OA Framework personalization to try to make Promise Date required, but the region for PO Details does not show as Full-View in order to force the required field validation.