That would probably work depending on there thickness, they do look quite thick.
I went down the route of drilling out the spot welds of the handbrake bracket and welded it back on lower. The nut on top swivel is already quite a bit thicker than the nut on bottom one so with the shims fitted it will make the seat height even taller. I like sitting as low as possible so that would make it too high for me but if it suits you then give it a try, it’s easier than rewelding the handbrake bracket.