Hey bro hows it going. Your getting really good growth, especially for the length of time that they have been in there....that's awesome.
Ice has an interesting lineage, my cut is sativa dom and I try and get as many bud sites on the upper half of the plant as I can. What are you seeing for phenos? The front one has pretty broad leaves, but are the leaves a little thinner on the plant in the back? If indica I would top and turn it into two three or four main colas and make sure you strip the bottom third after the 1st and 3rd week of flowering. If sativa def top and train and in both cases what I do is use string and good tape. Once your new growth is long enough use the string to spread the colas apart a bit and if sativa, tie those bitches down and promote as many upper bud sites as you can

so yes I would top them now fer sure!!