I have had success using multiple codes within a corridor template to create truly dynamic feature lines to define
curb returns and parking islands to name a few within the parent corridor as a baseline identity. I have coded my template as FG (finish grade) , Target (target elevations) thus and creating separate surfaces within the corridor using that naming convention, thus allowing me to target a feature line definition to the target (Target) surface breaking the circular reference problem, the result is a fully dynamic definition such as an island , retaining wall etc that is updated to accommodate changes in the template automatically with no further input, the feature line will also respond to being moved , altered or copied from one location to another and will take on the parent corridor elevations and re contoured