Hand held? Probably not.
On a tripod? Probably.
A rangefinder just is not the kind of camera I would use on a tripod (or any 35mm camera, for that matter, except for in uncommon situations)...therefore, the lack of a mirror has no advantage for me. It is not one of the advantages of a rangefinder, IMO (in terms of "camera shake"...not in terms of lens design/collapse-ability).