The architecture of the RM boards does not allow free channel patching, a 1:1 routing is an intended and proven feature. But you may want to make this to a request (StudioLive Series Feature Requests). Probably a request like this is already there.
You can not change the order of input and output channels, but the DCA groups (filters) allow some flexibility for mixing. This is an alternative to the patching of channels, because with DCA Spill it doesn't matter where an input channel is located. DCA groups can also be used to organize returns.