JPete, the MLD and BPL line tighteners are made for very thin line, possibly thinner than Triptease. (I did some googling, and nowhere, even on the Kelty website, could I find out the thickness of Kelty Triptease!) Both firms sell the tighteners only with their own cord, though. It might be that if you asked Ron Bell of MLD, he would sell the tighteners alone, and he could tell you if they'd work for Triptease. MLD sells their own reflective cord which is red, hence even easier to see than Triptease. It's 1.5 mm thick. I have some Gossamer Gear EZC2 line, also reflective and red, 2 mm thick, which appears (to my somewhat poor closeup vision) the same thickness as Triptease, but GG doesn't sell line tighteners.

I agree with Jim, Glenn and Eric: the taut line hitch is simpler, lighter and $0 cost!