As of SDK 3.0.9, the same Layers and Collision Matrix that is created for World Projects are also created for new Avatar 3.0 projects through the Creator Companion.
Previously, they were never set up for Avatars 3.0.
Dunno if this was intentional, but I thought I’d point it out. Especially because Avatars are specifically set to the “Player” and “PlayerLocal” Layers when uploaded to VRChat.