wolf, I went to 3under about 15-20yrs ago. Most of my bows don't have the ability to change tiller… and I do just fine. With the couple DAS bows I have I found that (quite coincidently) zero tiller is just fine on them as well…. Hope that helps.
PS- how ya aim isn't a factor in shooting effectively 3under… other than it lower your point on yardage.
I also shoot split and set tiller even, hold and groups are better for me.
On a bow order they ask (tiller split finger or 3 under) I call the bowyer and tell them even tiller, if they ask which I shoot still, the order is over.
Not being an ass I just know what I prefer and if the bowyer wants to build a bow that is a positive tiller just because I shoot split finger, that bowyer isn't for me.
Just to clarify I placed an order (see put on list) for a 3 piece takedown, non ilf bow.
I called the bowyer for choice of wood and such, he asked split or 3 under, told him I want an even tiller, his response "no problem" now the wait begins.