Dedicated crews are the tip of the problem. Boeing wants true 24 hour reserve crews so they can do last minute scheduling. Trips are scheduled when the the product is ready and they usually don't know until the last minute. Unless Boeing backs off that requirement I doubt there is any way to integrate LCF flying with line flying.
I see no reason NOT to integrate them!
With a -400 qualified crew force of a sufficient size, the reserve requirement can be met just like any other reserves. We do it seasonally for FedEx and/or UPS contracts as well as routinely for normal ops.
I suspect Atlas has enough pilots living around PAE and CHS to sit "ready reserve" without breaking a sweat. International reserve is well known to many of us as well...