Can't say I would collect those as there a too young and not a lot of character - Also good luck with them - they don't like direct sun and being fired in the the sun - least the ones I have had over the years.
Most of the hemlock i find grow straight straight trunked. The woods behind my house only has 1 hemlock and it is quite old, maybe a 6 inch trunk, nice movement, but is really leggy. It has the nicest bark I've run into on a hemlock, never seen anything but smooth bark on them. Not sure how well they back bud, especially on old growth. I have tried to read up and see if they air layer well but couldn't really find any info, would love to air layer it one of these years if possible, one portion has some nice movement.