Well, for a different approach to your wire length issue you can try this:
Build Wiring Packages that contain the wires you use for each assembly you install.
Example:
Package name
Wiring Package - Distributed Audio - Speakers and Source Control
Within a package, you can capture typical wiring topologies, hide the wire from appearing in the proposal, define a wire length that is different from the default wire length for the project, and define a default head end for the wire.
This is an excerpt from the thread below if you want to read the full details of it:
Just getting started...Have a few questions
Heather