You are right that it is the last thing to do when everything else failed. As many answered, there are several other ways to amend the design.
As a sketch, levels of editing are:
- Template library
- Template in Roadway Designer (or corridor)
- End condition exceptions
- Point controls, parametric constraints, curve widening
- Single template drop, features created by Roadway Designer
Everything done in 5. is potentially dangerous because manual editing (breaks rules), can be lost if corridor is re processed. But in some cases it is the only way to get the expected result.