Paint vs Powder Coat

[Hired_Goon]

If it was me, I'd just try and run a decent ground wire through the existing sheath to each switch. Once you "cut" into the powdercoating you run the possibility of creating corrosion in area you were trying to protect.

HG

[rustybones49801]

A smooth aluminum sleeve, like a crank bearing, soldered wire to that under the controls then run along the handlebars, held on with zero clearance zip ties routed to a grounding block behind the headlight? Or something like that? But since you have already cut into the powder coat, maybe some dielectric grease to keep the coating sealed and still allow the juice to flow? Just a thought.