I haven't actually done that in mid season, but as long as it is vigorously growing, I can't see any issues except the loss of this years crop. I would not hesitate to do it given the opportunity- I just haven't have reason or opportunity to actually try it.
I would go for it, and probably pinch the new growth at 8" or so and force some further branching later this summer.
I might even give it a fertilizer push a week or so before pruning to rev it up to force out some new growth.