How can I remove this thermostatic mixing shower faceplate?
I believe that chrome cap on the front of the knob needs to be removed. The valve I have is similar. Look all around the temp control knob for an inset set screw that takes a small allen wrench to remove. The other possible option is the chrome cap needs to be carefully pried off. In either case I think you'll find the key to removal of the knob is on the knob somewhere not behind the escutcheon.