Sure, but an instantaneous minimum "FPS" is invaluable when optimizing for an ideal gameplay experience. Just cap your framerate at that measured value and the result is console/vsync frametime consistency without the input lag. The addition of variable refresh means you don't have to deal with...
Sounds about right. I'm guessing the 'framerate averaging interval (in milliseconds)' setting is the time that's used to calculate min/max/avg when 'average' is selected.
I finally figured it out. Rivatuner by default calculates minimum fps (and maximum fps?) from an average instead of a singular frame. If you want the latter then change 'Global' > 'Setup' > 'Peak framerate calculation mode' from 'average' to 'instantaneous'. Hope this helps :)