The makers of Delta FL, a similar product to Platon, also recommend concrete screws, each one coated in silicone before being driven. Properly installed, both Platon and Delta FL serve as moisture barriers, directing moisture to the perimeters of the installation. Powder-actuated tools provide no way of sealing the fasteners. More importantly, the tops of the fasteners have to be flush with the ply or OSB, so you can install finished flooring. Powder-actuated fasteners sit above the finished surface.

Thanks for the reply, Worthy. I don't remember silicone in the Platon directions, but that would make sense to do it that way.
I have another question. I'm thinking of building the walls on top of the platon/osb to keep the wood away from the floor. The directions recommend keeping the platon membrane .25" from the outer wall so the water vapor has somewhere to go. I am still debating on whether to use xps on the concrete walls or spray foam.
Here's where I get confused. If I go with xps on the walls, I'm thinking the order of operations is: install xps, put down the subfloor, and frame the walls. Pretty straightforward, I think.
If I go spray foam I'd likely do the floor, build the walls on top, and then have the foam sprayed on. In that scenario do I need to take special care to avoid sealing the platon up with the foam on the walls?
Do you see what I'm getting at?

SPF installers can work with the stud walls in place. But it would seem simpler to me to insulate the foundation walls first--either boards or SPF--then lay the Platon down leaving the gap they require for expansion per the directions and finish with the framing. (You can use the powder actuated fasteners for the stud walls.)

If you want more than Code minimum R value you can fill the stud bays with fibrous insulation.

Worthy's installation steps is what I used when installing platon in a basement bedroom. It's a pain to drill the holes and then seal each one, but that way you get everything nice and flush with the subfloor. Floor is much softer and warmer after being lifted off the concrete.