Never used a MinoreIII but that seems like a fairly low steam boiler pressure? The advantage of being a double-boiler is that you should be able to dial up the pressurestat. Someone else will know.
BUT, I reckon a 1 litre jug is always going to be less successful and (more importantly) less fun than a smaller jug. Who cares if it take a little longer; at least you get twice as much steaming practice and double the latte art potential! Just my opinion.