I have grown out most of the Mandala straines, but I haven't tried the Hashberry as of yet . I have the seeds just do not have the time or space.
From what I have seen if the Hashberry is a short Indica like the Satori I would not top. Even for a short plant they produce quite a bit of bud on a sizable main cola. Since you are starting from seed I would veg for at least 6 to 8 weeks, which should give you a plant of about 16-18 inches going into flower. Which should give you a plant of about 25 to 30 inches after strech. Do not feed for the first several weeks, only Ph'd water. Then you can start gradually increasing the amount of nutes from 1/2 to 2/3 to full over the next couple of weeks. ( I use the full lineup of Fox Farms Nutes). Hope this helps a little. Good luck.