Slice or not to slice

this is prob gonni be no help to you at all , but ...... I sliced off a bit of growth for one of my non stop Begonias that has started to grow and ive potted it into a 3inch pot just to see what happens , now i may done the worst thing poss to this poor plant and it may go and die on me ! but I thought id give it a go and see what happens !

I was assured by an experienced almost exclusively begonia gardener that she halves the bigger tubers every year. I can't speak to her every week as we sort of pass working hours 'out of synch' so I can't get the info I'm after....Thanks for your response...

Ask Marksbegonias - I am sure he must have done it!