Also, afaik, Bisq has no limits for buying/selling Bitcoin (depends on the payment method though), so technically you could buy/sell corn within 0.1-1 BTC (insanely high amounts for me, some people can apparently afford it). 

 I think going above this level of stacking bears serious risks anyways, regardless of KYC or not. So breaking down the fiat stack and purchasing small portions of corn sounds like a reasonable alternative to me.