Rotax ring mount bolt shoulder clearance

The 912 ring mount holes have an internal diameter of about 10.8mm, while the diameter of the shoulders of the M10 bolts that have been supplied in my (Sling 2 incidentally) kit are about 9.6mm.  So there is about 0.5-0.6mm clearance all around.  I could take up all of this gap using some (nominally) 11mm diameter 0.5mm wall thickness stainless steel tubing which creates a snug fit.  But is this actually a good idea?  Is this gap actually required?  Note the other end of the bolts go into rubber mounts and steel tubes as per the IM.  I have been advised that this gap might protect the bolts against shear failure in the event of a rubber shock mounts bottoming out, and to absorb tolerances in the engine mounting frame.  Photo shows shim partly inserted into the ring mount, it is just slightly shorter than the ring mount bushing.