I wouldn't think it does anything, going to empty pins. Maybe it does something on the 500E upwards. Those models have an EQ bypass and a mids EQ switch.
Hard to tell but there's about 20 mods done so far to this USA Elite JB. All the Alperious plates (5 total) are current being worked on as I'm writing this. Will post a ridiculous mod list as a thread once everything's complete (prob 4-8 weeks)