ehhh yeah i know your asking you want a threadless one, so you SHOULD have a compression so it works to its fullest, but on the contrary they offer .120 wall which you could just get that WITH threads, and it still really wouldn't matter
no, but if you get threadless a compression system is a must, i had 6 clamps tightened to the max without a compression system and it still gets loose very fast
so i would just get threaded