I did that last year. I cut my big tops...cut stem flat across and not at 45 degree angle ( I don't like to expose too much of the stem surface ) I trim a few leaves that are stopping sun from inner bud's...should have done that a little earlier, and they were fine. At that point stunting isn't really a concern...your just fattening up your remaining buds.my main stem is pretty much done but the outer stems on my plants have like 90% white hairs, if i cut the main middle stalk down will the sides still continue to grow? or will it stunt?