Just found this quote online –
We were fascinated by Joe Maiden’s article in Kitchen Garden (January 2012 issue) where he described how he accidentally created a multi-cordon Sungold tomato plant,when one of the plants fell out of its box prior to planting and snapped off the growing point of the stem. The plant grew sideshoots, which Joe decided to train as cordons, creating a multi-stemmed tomato plant. He removed the side shoots that grew from these new stems and ended up with a 60-truss plant by the end of the season!”
Could it be worth a try? 