Brian,
What you are asking is quite a "age-old" issue. Here is one older solution (SS2, pre-OR) that would have to be modified a bit to work in OR, and would not get you anything but final design broken into pieces. The temporary detours, etc would still need to be created as individual corridors, but that was true both pre-OR and now.
The one spot where OR could be leveraged as a benefit over SS2 would be with corridor clipping. Let's say you are doing partial construction and only half of the road will be built in Ph1. Well, you could reference the overall design into your Ph1 file, then clip out the part not being built. If you needed a temporary end condition along this edge, you would need to create a linear element that uses the proposed pavement (or FG terrain) as its vertical, then run a linear template (or corridor) along that element. This is just one example, there are probably others as well.
I will also add that the good news is that Bentley is fully aware of the difficulties involved with this process and are looking into more efficient solutions to provide our users.