i recently picked up a Fantom XA with a scratchy master volume pot.
at least one post on this forum mentions a similar problem and the possibility of a bad motherboard
I think you are mixing up information from different and unrelated posts. A noisy pot is a noisy post and if cleaning doesn't help it's probably best to replace it. I would contact Roland to obtain the original part, I believe their prices for replacement parts are not entirely unreasonable in most countries.