Top it. You are in Veg, control the plant to the size you want. I purposely want short plants myself, so I don't allow them to get to tall. I LST them and top 'em. Check the T5HO vs. HPS thread for my examples, the original mother was 5 feet tall.
Mine are finishing at a max of about 16 inches, two at only 10 inches with multiple "Main" Cola's. That's why I like the T5's, they don't shoot to the sky if you keep the light close. (like under 6 inches close). I wack their heads off in veg,(I am doing 3 of 4 without topping this round to see what happen's) and tie 'em down.
Control the plant I say, don't let the plants control your space if you can avoid it.