I suppose it depends how reflexed/deflexed...and how much the limbs are trapped too. I would say narrowing the limb itself usually doesnt cause twist, but instead makes variations in the lam stack thickness side to side or errors in the side profiles more impactful, and thus twist will occur.
On my 60" highly R/D bows (about .370 total butt thickness lam stack, with a .003 taper per inch), I am usually at 1.25" at the fades straight taper to a .500" tip. I have about 8 degrees of trap on the back of the bow. I don't go much thinner than that.
On a very mild r/d bow I would go down to maybe 1.1" at the fades.