Patch changing via CC is covered in section 5.5 to 5.6 of the manual you’ve linked to. As JMCecil said then use a Quick Controller in Cubase to change patches on an automation lane in Cubase. But this will just switch patches, not change parameters.
On the Sysex dumping front, I see that as section 5.7 through to 5.8 but yes I’d start with those. The manuals are rarely intuitive unfortunately so you may need some experimentation.
I’d just test sending the single patch to a MIDI channel first, then change the patch on the PCM91 and try sending the change back. Section 5.6 tells you how to allow the PCM91 to receive Sysex data (make sure to turn it off again afterwards).