Here is what it did: I used an M3 bolt (diameter of the Supernova mount) that I mounted with washers and taped with heat-shrink tubing inside the M5 rack mount so it doesn't move once bolted. Been running this for two years now.
That would be a nicer option!
I found these at home, unfortunately they're half a millimeter too big…
I'm afraid pushing it through the rack eyelet would destroy the threads.
Here is what it did: I used an M3 bolt (diameter of the Supernova mount) that I mounted with washers and taped with heat-shrink tubing inside the M5 rack mount so it doesn't move once bolted. Been running this for two years now.