flat epdm roof problem
If you were going to try to patch these MARS plates and screws, I would probably completely back the screw out enough to fill the screw hole in with the manufacturers approved lap sealant, so that when you re-secure the screws in place, the threads are pasted with this product.
I would also liberally apply a continuous circular bead under the disc prior to it becoming screwed down, just enough so the disc pushes the additional sealant out of the circumferance of the plate.
After it oozes out of the outside diameter of the plate, I would take a "wet" finger, and smoothen the bead of sealant down so that the bead is equally high as the securing plate and tapers down to the epdm roof membrane.
Not an approved manufacturers patch, but it will keep the individual screws water-tight probably.