For variable refresh rate without (much) tearing you turn vsync off in
game settings. That's how you get the highest frame rates as your
benchmarks show.
It's true that the highest framerates are achieved by disabling vertical sync. However, my understanding was that if my system can deliver sufficiently high minimum framerates, vertical sync can be used with consistent frametimes (minimal or no stuttering). I used vertical sync this way with games on Windows years ago, and I believe this is common. That's why the stuttering with Vsync on in the above Mountain Peak & Geothermal Valley examples was unexpected to me.
I tried disabling Freesync on the monitor after seeing Reddit threads with Windows users complaining of stuttering with 10-bit color depth & Freesync while using other Radeon GPUs.