I still think that even with frame limiter to below the FS and VSync on you will not get FS and have the VSync lag because the actual Hz counter on the monitor was also hitting 70 Hz. No, again, not what happens. G-Sync / FreeSync do not switch over to V-Sync when FPS = refr...
Did somebody try Freesync + RTSS RivaTuner FPS Limit -2 or -3 your monitor Hz + Enhanced Sync (and disable V-Sync in-game)? I know that you can find test of G-Sync+RTSS+Fast Sync on BlurBuster (https://www.blurbusters.com/gsync/gsync101-input-lag-tests-and-settings/8/) but ...