As much as you like but you need time to recover so there is a point that you want to stop
Top once you get 2 colas top them two get 4 and so on i recommend only doing it 2 times but its up to you if you want to veg your plant for 3 months then top like crazy
Ive topped my plants multiple times to see differences between them. The most I've topped was 5 times although, I had a ton of buds they weren't as full and dense as the buds on the plants i topped 2 or 3 times so be careful to how many times you top man.
