cutting the vine when it actually vines. and by the time its 5 feet tall , it will probably be about 4 feet in diameter or more. im not 100% sure how fast it grows though
I have heard of growing bicalcs in less than ideal conditions to slow their growth. However they are notoriously quick growing. One option is to grow it until it gets too large, then trade it away for massive quantities of smaller plants or ebay it for massive quantities of money. Although, keep in mind that shipping such a huge plant is no small endeavor.
if you keep a bical root bound in a small pot it will stay smaller. each time i repot my bicals, they have huge leaf size jumps.