You don't lose a tick in that sense but you lose potency on each individual CT and phleb if you clip. If you don't get every tick on CT then it's no longer worth 350 potency. Say you lose 2 ticks, the value of each individual CT is now worth 280. So yeah in a sense you do gain a bit of extra potency on fracture, just not enough to overpower the loss of one geirk per minute and the delays on your other abilities . Not to mention when you refresh a dot it'll refresh with your current buffs (or lack thereof), so the buffed tick that youd get by waiting the full duration is replaced by an inferior tick (assing you applied previous dots with buffs).