I've been wrestling with this myself. I build all my recurves at 64" and an even tiller seems to be best. I've gone to 1/4" negative (weaker bottom limb) and the arrows kick upward wildly though the bow is quieter and less handshock, to 1/4" positive, which seems to be the lesser of two evils, but even tiller is best. I do go with a high brace, 9" to 9 3/8" which isn't too extreme since I build a forward handle like Black Widow does. I confess, I only check tiller at brace height. I haven't messed around with checking at different draw measurements. I should do that. 8^( I use basically "Whooly Whispers" (I make my own) and put them at 12" and 18" from each string loop, 4 per string and the bows shoot fairly quiet. Changing brace height seems to have the greatest effect on quieting and reducing handshock. I build 14 to 18 strand, Flemish Twist, TS Plus strings with Crown serving. I'd like to try some stretchier materials to see how quiet you can get a recurve without losing too much arrow speed.
For what it's worth, Steve