Bumping for more active input.
I suppose it's a possible thought. Sage Mode user getting Rinnegan implants, I guess that wouldn't exactly be completely out of line, though they would suffer deficets if they didn't have the proper body to handle it (use more chakra is all).
So while I guess it's possible to legitly do it, that only reinforces the point that someone would attempt to claim it at some point, especially since we've had this little discussion. xD
I highly doubt this is the first time anyone's ever thought about that happening >.>
I like to believe someone hasn't tried to seriously do it yet because they know that literally no one would take them seriously.
Also from the recent chapter revelations, isn't it implied that the Sage of Six Paths is called that because of him using Senjutsu (Sage status) and having the Rinnegan (of the Six Paths status)? This seems to be the case for Obito, since it's been identified that the jutsu that he is using is Senjutsu-affiliated?