I wouldn't ride it on 4 bolts. I've broken those bolts coming out of the saddle for a steep pitch. Fell to the wrong side and while I was not moving, the pavment was long ways down. Not fun.
(Aside on Avocet. They told me that was what I got for riding with the bolts loose (which I doubt). Since then, every other piece of Avocet hardware I've ridden has also broken. Retired those cranks for SunTours. Pulled them out "for the time being" to set up a new/lod bike and broke the crank across the pedal threads very early on.)
Sugino quality, even on their cheapest stuff, is good. You might get away with 4 bolts. I wouldn't try. Now, on a properly seated big or inner ring with 1) its far better support from the very short bolts and the nice fit on that shelf and 2) considerably lwer chain forces since the radius is higher - I"d ride that with no concerns at all, Juxt check the other bolts a little more often.
Ben