The first thing I do after floor tillering is place the bow on the tree from the center to make sure the bow balances. I can't long string tiller without doing that.
The subject of limb timing comes up now and then on here.
Wood is not uniform. Even within the same stave it can have different properties. If your stave is a knotted, twisted piece of wood, timing can be an issue especially when you can't achieve that picture perfect tiller.
I want my limbs bending equally well and returning at the same time.
I can see that on my rope and pulley.
Call it what you want.
I call it limb timing.
FYI I tiller from center and finish tiller either by feel, mirror or digi pic.
Jawge