I do agree that hardwiring the ground connection on RCA connectors is certainly better. Relying upon the bolted or pop-riveted connection to the chassis was quite common back in the day. And electronics had to be built to a price-point too. Certainly, if one is having a problem with a Sunn footswitch, this should certainly be checked .....we've all seen the surface corrosion on a Sunn chassis! However, I would not consider hardwire grounding of these jacks to be an imperative .....I've never had this problem with any of the Sunn amps I've repaired over the years. While it couldn't hurt, I prefer to only fix functional problems on vintage amps, leaving them as original as possible (within the parameters of safety). Just my 2 cents.