Ok, so no flange and no self locking feature. There are 129 nuts of various sizing and types in use on the gen 1 Vmax. Most are cap/crown type nuts and most have a flange (with or without locking serrations). The few that are 6mm and don't have those features include:
(1) on the brake lever that serves as a jamb nut for the plunger depth screw
(2) on the rear reflector that hold the mounting bracket to the grab rail (these did vary some from year to year)
(1) on the rear fender where it bolts through the forward hole of the grabrail (under the seat). Usually this is a self locking but I have seen regular ones
(2) on the rear taillight holding the light assembly to the metal inner bracket of the rear fender
(2) inside the speedo cup holding the speedo to the mounting bracket
(1) holding the fan blade to the fan motor
The rest are noted are either self locking, have a flange, or are cap/crown nuts (or bigger size). Having said that. There are a LOT of welded on nuts to various brackets. Sometimes (rarely) these can break free. I do not see indications of that on your picture.