For anyone having issues configuring UEFI boot parameters when configuring boot-from-SAN, I believe I have figured out a CLI solution, which is much better than the workaround mentioned in the bug report. I have documented my workaround here:
CSCvt79874 - Cannot set UEFI parameters for SAN Boot in UCS Central - Cisco Community
(I wish there were a way to have posts created from a bug report, added to this Unified Computing System Discussions board.)