The new Avatar Joint Feature (Physics based avatars) are compatible with custom starter character?

Roblox Added a beta fetaure that i want to use for my game wich is the Avatar Joint Update wich completly replaces all motor6D of an avatar with AnimationConstraint that make the avatar more “ragdoll” and “realistic”.

[Studio Beta] Avatar Joint Upgrade: Enabling Physically-Simulated Characters

Im going to use this update for my game, and I also need to have a custom character, i have tried to do it the regular way wich is just grabbing a random chrt from the toolbox, title it as “StarterCharacter” and put it in the Starter Player folder, but that did not work since it did not changed the Motor6D with Animation Constraints, wich made the feature that i was using not work

I wonder if there is an alternative way of using custom character, while conserving all of the changes the new update makes on the avatar