McCLIM support for setf*

Does McCLIM support the Multiple Value Setf setf* form of the CLIM specification? Is so, how are such forms supposed to be called?

For example, consider (setf* window-viewport-position). Should it be called like this?

(setf (window-viewport-position) (values x y window))

According to some examples in the McCLIM code the correct way to call window-viewport-position is:

(setf (window-viewport-position window) (values x y))

I forgot to mention that I checked and McCLIM does indeed support Multiple Value Setf forms.