Thanks for contacting Intel Embedded Community.
Intel's suggestion in these cases for undocumented implementations is that these should be tested and validated from the customer side. The conditions and guidelines tested and confirmed by Intel are stated in the documentation.
Yes, I understand that this is Intel's position, but my question is really around how we can actually get this configuration to work. Is this something in the MRC that is fixed and hence will never work, or is there a way that the FSP can be made to recognise this configuration? So far we have tried and failed to make this work but cannot see why this should be the case.
It is likely that the MRC code will need to be modified to take account of the unsupported configuration. I'm not sure whether you have access to BIOS source code but, if not, Ircona could either provide it to you or assist you in finding a working solution.
Please let me know if you would like to discuss this further