No, DMRlink can not act as one end of a CC-CC link. That protocol, like BrandMeisters FastForward is proprietary. We have discussed trying to get together with the c-Bridge and BM people to layout a Open Source server to server protocol. We think this would be great addition to the HAM community in general.
In their basic form, there is no control of what TGs are sent between the two partners. That type of control would be external to the partners. Conference Bridge could be used to control what TGs were passed to "client" repeaters and servers.
As we move forward, DVSwitch Will become part of the mix. Rather then having Partners connect directly together, Partners will connect to DVSwitch and DVSwitch will control the routing data. DVSwitch is in early conceptional form. The questions and comments will help us better design the tool.