Technically, CC #64 can be used for functions other than damper pedal - called "non-standard controllers" - so it wouldn't be good to disable the full 0-127 range outright. Also, according to the MIDI Spec, values 0-63 are supposed to represent "off" while 64-127 represent "on." Zero and 127 are more typical (and intuitive) with switch controllers, but your pedal is probably operating within spec.
All that being said, I agree 100% that editing CC data in the PRV can be frustrating. Any improvements here would be welcome.