I've split 2 so far myself. That's the strain. the branches get so thick so quickly that they don't like to bend. Then when I untie them, they straighten out a little. I taped them up and they healed just fine. Unfortunately it makes the grow lagg a little, heal time.
Those ones I topped right when they hit 8 inches. The girls I let grow over a foot then chopped in half, do not seem to have that problem.
Ive started 3 batches of 5 in each. I have learned from my mistakes along the way. I think I got it down. The 3rd batch is vegging faster too (same strains).