Availability of EFF for Purchase Requisition / PO (RSSP)

Summary:

We have a requirement to capture a Prepaid GL account at the distribution level of the Purchase Requisition (RSSP) page.
Due to the character length limitations of Descriptive Flexfields (DFF), we are exploring the use of Extensible Flexfields (EFF) for this purpose.
However, we are unable to locate any relevant EFF attributes for Requisition or Purchase Order objects in our environment.
Could you please confirm:

Whether EFF is supported/enabled for Procurement objects such as Purchase Requisitions and Purchase Orders
Specifically, if EFF can be used at the distribution level in RSSP

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