Tristar AKA Triamble.. will go where you train it, you can direct the growth, 3 plants will take up a lot of room so be careful to keep an eye on it, they have extremely vigorous vines and can grow more than 25 feet ,the straight leader will side shoot , 8 pounds in weight.Great squash by the way(called pumpkin as it is Australian and as you know all winter squash are so called down under). Feed well if in a smaller space than it should be. Good Luck.
Don't understand your problem with corn, can I help?
XX Jeannine