Just as a follow up to this, in case anyone was keeping score. I did talk to DP about this... he said that he had sent his Lunatec in for other reasons but while talking to their service they said that they could add the switch. He said it cost a couple hundred bucks or so to have it done.
In the meantime however, I realized (or rather remembered) that the 722 could decode m/s on the fly so, even though it would be easier to adjust the gain on the V2, it seemed a bit of a waste to have the switch added to my V2 also. Also, I've pretty much only been doing m/s post anyway.