"Free-Patching" Stereo Channels

Hi,
when connecting a stereo paired channel to sockets, you can only use consecutive sockets starting with an odd number, for example:

Stereo-Paired Channel 7/8 → Socket 11/12

I know that normally this is completly no problem – but why is it not possible to patch “freely”? It could be helpful if you get the rider from a band, prepare everything, and they finally come to stage with a different setup. In such cases a free-stereo-patching can help, for example:

Stereo-Paired Channel 7/8 → Socket 12/21

Best Regards,
Tobias

PS: @Hugh: If you really need to answer this, please be polite and helpful.

+1
So useful for audience mics and similar.

Crazy sockets are tied to the stereo inputs.