Hi there, 60cm height is definitely on the shorter side for a tent, so you'll have to do some LST to keep them small.
One of my boxes is 70cm in height and I had to move my "bonsai" out of it (you can see my white haze diary), because it started stretching too much.. It wasn't a great idea to put a Haze in there anyways, as they can stretch a bit, but i hope you don't have to go through similar.. Looking at the purple punch, they should stay a bit smaller than my haze anyways..
happy growing!