Read about it in the map chat few days ago and just tried it at the Temple of Melandru.
When the Priest transforms you to an animal and you pick up a weapon, you get your equipped weapons skill bar back. Swapping works, F1 skill doesn’t. This might be possible with a previously placed Fiery Greatsword (Ele skill), but I tried it twice with the Diving Goggles which are placed conveniently there and worked.
So I could fire the Acolytes with my rifle (or leap with my sword), which makes this phase much easier if everyone used it.