Hello!
So this is a yes and no.
They have validated my form but the withholding is still at 30%. Even though I have provided everything they need to see that Switzerland has a tax treaty with the US including the TIN (Tax Identification Number). Now I don't know if the 30% are accurate or not, but I have not gotten a reply from the Itch support nor the tax support on that matter or about my questions either.
So it only is partially resolved