I think what I'm trying to say though is that there's no benefit to starting with one tooth if you have already paid that "startup cost". Since at that point the cognitive load of flossing one tooth vs flossing all your teeth is basically nonexistent.
One tooth is strictly less time, less commitment, less cognitive overhead than all your teeth.
Simple as that.
Of course this is just the regime that helped me build 4 or 5 brand new daily habits in under two years, all of which I had tried and failed several times before. YMMV.
