The currency translation that used to be in FRx (DAX tables) has moved to the source ERP.  Management reporter will then read the natural/originating/functional currencies directly from the GL.

There is one deficiency to note within AX, please reference the following enhancement request submitted for Management Reporter.  Microsoft replied that this is an enhancement request for the AX product:

https://connect.microsoft.com/dynamicssuggestions/feedback/details/678874/mr-for-ax-needs-additional-currency-functionality

https://connect.microsoft.com/dynamicssuggestions/feedback/details/672477/mr-should-allow-each-column-to-have-its-own-current-rate