After Conductor Release 122, Sprint 16 on 9/22 site, codes should be more functional and correctly create the long extension for sites and users. This feature is still in beta as the platform team expands the endpoint's features to be more robust but you can set site codes in Conductor right now!
The current limitations:
- Site codes must be enabled before build activity starts.
- A site code can only be set once through Conductor.
Best practice for site codes is to consult early with the customer and find out if they really need to use site codes before creating the workspace. In most modern telephony builds, site codes are not needed, and if incorrectly set, they can greatly limit the extension possibilities for an account. It is likely that the customer wants to mimic his current build but this is an opportunity to inform them of all options.