Suppressing tenant prefix on device user names

I have many pre-existing end points on a different PBX system that are already configured with device user names that I would like to migrate to VitalPBX. Some of these devices are hard-provisioned and are not easy to reprogram.

Is there a way to suppress or override the tenant prefix on a given device so it can use the user name I provide? Right now it wants to use T7_{username}. I want to just use {username} that I provide.