Hey, I love it.
Dunno if I'm maybe missreading the photo, but it looks like your tillering rig is supporting the bow at
two points and not allowing it to pivot freely.
I'd be interested to see it on the tiller supported at a single point, that 'out of parallel' effect may not look so bad.
This is one of my pet hobby horses. I think the tiller should ideally support the bow on a rounded leather pad or somesuch to mimic a hand.
I've had bows which look vastly different if you just move that support point by an inch, and supporting it on two points is almost like holding it rigid.
BTW, string angle of 90 degrees is surely ideal, all the force is perpendicular to the limb, any other angle has losses.
So, like I said...I love it...I like to see the wood working hard to earn it's living
Del