Yes of course.
I'd rather not though. But if you must -
Mill the base thinner and cut the base to tabs shape. Getting the detent right for the orange ball to engage in properly would be a headfk - so I'd cut it to FSC1 sizes and use the grub screws (as FCS2 can accept FCS1 dual tabs)
I ask because K4 doesn't have any FCS fins as far as I can see, but they do have slot box, and I can't find any FCS fins anywhere that are offset.
I can always just run it as a single so it's not a big deal.
