How thin can a platinum ring spacer be made?

[jenpm78]

My stone is set low in a six prong, 2 mm plat setting.
I''m not a fan of curved wedding bands.
How thin could they make a ring spacer for me? Or would notching one of my prongs be a better option?

Thanks.

 

[Garry H (Cut Nut)]

usually nothing the prong is the answer

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