Guys are using cam cleats on Mission platforms, so I recon it works. I haven't tried it.
Seems like you need a third hand though. You're hanging, holding the platform up, swinging the rope around the tree, guiding it to and through the cleat.
1 stickers are mostly working hands free by wedging the top step under the tether. Red Beard tensions the solo scout against the tether with side pressure (but it is a small light platform). With the bigger platforms, I worry about that 5lbs working loose and smashing about me. Cbigbear is quite efficient with the strap slide approach, and that simplifies movement and adds some control.
Maybe a sort of hook on the platform to run the tether through with a sliding stopper would provide a more secure feel? Idk. Or perhaps something like a v cleat mounted to the bottom of the platform could work, not for securing the platform to the tree, but for temporarily locking the platform to the tether until the platform rope is run through the cam cleat. The geometry would have to be correct. Maybe I'm just over thinking it.