Boundary scan access to SDM pins on Agilex 7

In the Agilex 7 BSDL files available from the Altera website, all of the SDM pins are marked as 'Linkage' indicating that there is no boundary access or control of them.  However, from some early investigations on the DK-SI-AGF014EB Development Kit it seems that boundary scan can be used to read and control at least some of these signals (so far I’ve tried SDM_IO5, SDM_IO7, and SDM_IO9).

Please can you clarify why this functionality isn't included in the supplied BSDL files, and whether there is a way to obtain BSDL files which include this information?