Travis,
I'm probably a little off-base here, especially as I'm not quite sure what you mean by "migrating crown", but in my personal
experience, if you don't need the links beyond the back of kerb (BOK) to run perpendicular to alignment 2 (i.e. if running
perpendicular to alignment 1 still gives you the result you're after), don't use an offset; use the logical settings in the Corridor
Parameters tab. This will reference everything off the centreline alignment (alignment 1).
If your "migrating crown" is what I think it is, would adapting the LinkSlopesBetweenPoints subassembly help? I foresee some
drawbacks, but I don't know your exact situation...
Hope that helps,
Trevor