If plating is key to obtain electricity in this concept, I tend to think it also related to the ionization of at least part of the gas applied (air or hydrogen).
Open question: Is there a plating thickness range where electricity is generated? Outside that thickness range no electricity?
Another thought related to plating is that hydrogen is formed at the plated electrode (cathode) when electroplating is applied in a H2O solution. This could cause hydrogen storage within the plated metal, which could be the fuel even if a LEC is filled with normal air. To confirm, a freshly plated WE should be degassed (e.g. by heating) before applying it within a LEC setup, to see whether electricity is still generated with a degassed WE or not.