Since BOSSv3 is now LOOT, the BOSSv3-related changes to BOSS's launcher should be undone, and a new launcher added for LOOT. @lojack5, do you have any pointers of what would need to be added for a new launcher?

The BOSSv3 masterlist/userlist locations should also be updated to point to the LOOT locations. Replacement of the API isn't part of this issue, since it works well and IIRC there haven't been any relevant changes in LOOT since the API revision Bash has.