Good pics, Dan. You're doing OK. I wouldn't pull any further with that loose string. You can go from floor tiller to some low brace. Its more accurate pic of your true tiller. Those flats will bend but you have to take them slowly. The deflexed areas too, but they are deceiving in that they appear to be bending.
I like the tips to ultimately move the same distance, regardless of limb lengths, and even curving limbs. Others want more symetry.