The advantage of a margin loan is that the holder only exposes himself to fx risk of the pnl portion. The broker loans the purchase price/margin/...and that goes back to the broker upon liquidation. The difference is exposed to fx risk. Same as a house purchase on mortgage in foreign currency. The fx risk is not applied to the house value but to the realized pnl upon sale.
Advantage compared to what, being unhedged? OP is using futures to hedge his FX risk. This should give basically the same results as a margin loan shouldn't it?