The setting is intended to allow the operator to run in V3  with either single-domain or multi-domain setup.

If value is False, it refers to running either v2 or v3 but single domain.  The user won't be prompted for Domain on login.

I am afraid that changing the name to something shorter won't make it unclear for the user.  The configuration name is already used in horizon. If this is set to True and Kesytone is in V3, we display the Domain management panel.   

If you really prefer shortening the name, I can make the change here and in horizon.