The tiller discussion comes up quite often and IMO it just isn't that important--unless we're talking about a self bow or a VERY short glass laminated bow.
All bows have tiller. It usually ranges from 1/4" positive to 1/8" negative.
Think of like this--maybe, to get an idea of the perfect tiller for the individual archer.
Imagine two doors on a wall; now, slam the doors shut. If they slam shut at the same time, there is little noise or vibration. Let one door slam at a different time than the other and you get noise and vibration. The idea is to make adjustments so the doors (limbs) shut at the same time. It's more about timing than actual tiller.
Raising and lowering your nocking point will change the timing; raising and lowering the shelf/rest will change the timing; heeling the grip will change the timing and putting more pressue in the web of your hand will change the timing.
There's too many variables to claim a bow is tillered for split or 3-under, etc. Most times you can simply tune the bow and shoot it without issue.