What I have learned is that tuning is relative.

Due to how our ear perceives the pitches, and a multitude of other factors contribute to how pleasing to our ear, the pitch, or combination thereof, sounds.

You can tune a piano with a strobe tuner to perfection however, when you play certain intervals they clash necessitating that one of the pitches be altered slightly.... putting it out of tune, in order to sound pleasing. A friend who was a piano tuner by trade told me about this phenomena. I was watching him tune a piano at a concert hall and noticed that while the rest of the strings were dead stop on the Conn Strobetuner, he left certain ones slightly flat and moved on. I questioned him about that and he not only explained it, but showed me by tuning the strings to dead on stop, playing some chords, and then adjusting the notes back to slightly flat and playing the same chords again. Quite amazing..... because if you play those notes in other chords and in solo scales.... you didn't notice they were flat.

A similar situation exists on the guitar. Due to the physics of the various thicknesses of the different guitar strings, the amount of wear on those strings, the fret spacing, and the bridge saddle positions, you can play hell trying to get and keep a guitar in tune in order to play chords and inversions across the neck. As one gets to know ones own instrument, and has worked to get the intonation properly set up, one tends to know that leaving the G string a few cents flat in often the best compromise when it comes to tuning.

I only watched a small section of the video..... I'll try to finish it later this evening to see if they address these topics and issues in the remaining part of the video.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.