Playing a mass fabrication character and one of the other players pointed out there are a few ways to get two valet familiars. While it's obvious the +2 wouldn't stack since it's a bonus of the same type we are wondering about the "doubles the gp value of items that can be crafted each day" part. Probably a silly question but can't seem to find an answer.
I would guess that it works, following the standard rules for multiplication, so 2 doublings makes it triple etc.