DFCs and PFCs is stated in the release notes and config guides for the related HW:
Configuration restrictions with PFC3BXL/DFCs:
-PFC3BXL and DFC3A-PFC3BXL functionality is restricted by the DFC3A: the
PFC3BXL functions as a PFC3A.
-PFC3BXL and DFC3B-PFC3BXL functionality is restricted by the DFC3B: the
PFC3BXL functions as a PFC3B.
-PFC3BXL and DFC3BXL-No restrictions.
In other words, okay to mix but expect the performance to be consistent with the what ever DFC is mixed in with the PFC3BXL. I hope that helps.