Haha, good. Not sure how high you are planning the cakes, but with this stand, once the cakes are in place, there is a tendency for the weight of the cakes to pull them down slightly - mostly because the stand only has that single arm supporting the cakes. So you don't want your cakes being too high or the bottom of the above cake will practically sit on the top of the cake below.
I have heard of one or two incidents of the little feet going right through the white cake boxes, so you might want to be careful.
I have done several cakes directly on the regular separator plates and not considered the extra inch or so that the feet take up, haha, which is why I wanted to mention that, I had to scramble to get deeper boxes, duh, I am an idiot, haha!
For a really heavy cake, I prefer to board the cakes and this is why. Sometimes the cake is so heavy that when you set the cake down when it is directly on the separator plate, there feels like there is some give to the plastic plate. Now this might very well result in some icing cracking issues.
I have actually had one Wilton Decorator Preferred Separator Plate crack down the centre and it was only being used for a 6 inch high cake. It likely was a defective plate, but that always made me a little wary.
Be careful when trying to slide or move a cake that is directly on the separator plate, sometimes the feet stick. Also, if you decorate on a turntable, the feet don't sit in the right place, haha, found that out too.
There, hope I didn't scare you, but that is my knowledge of these plates.
I think you now have all of the possibilities and precautions and are probably wondering why you ever wanted to do cakes in the first place, haha!
Hugs Squirrelly Cakes