Re: Rizoma Reasets non high-mount campatible?
as klagdon says, the issue is the possibility of interference between the S pipe on himounts and the rearsets. You may be able to significant reduce the possibility of interference by replacing the lowmount pipe "arm" with spacers of the same thickness behind the rearset mount. This arm is not attached to the rest of the rearset- it simply sit underneath the rearset and shares a mounting hole.
this is likely to cure interference, but I cannot guarantee you won't still get some interference from the rearset itself, since it's nonstandard.