This question is a follow up question to this http://mathoverflow.net/questions/57235/automorphisms-of-sl-n-mathbbz/57236#57236 question. So my question is:

For which rings $R$ (commutative, with unit) (and which integers $n$) is $Out(SL_n(R))$ a torsion group? A consequence of Theorem A and B in O'Meara The automorphisms of the linear groups over any integral domain http://www.reference-global.com/doi/abs/10.1515/crll.1966.223.56 is that this is the case (for $n\ge 3$) for any integral domain, whose underlying additive abelian group is finitely generated.

However this is just a computation and I am wondering, whether this question has already been studied somewhere more systematically or if there are other results that also have such a corollary.