Ya.. transplanting.. go up to the main leaves, a few inches down (assuming you haven't stretched the crap out of it)..
That main stem if you bury it and don't abuse it, will root out without hesitation.. it is dying to in fact. It wants to root into soil and provide as many nutes as it can to the whole system.. Be reasonable, but yes, Bury main stem on replant if you 'can'.