I'm a violinist! The answer is "it depends". There are so many complexities to tuning that relies on harmony which is continuously changing. Mostly it is done with careful listening and intuition. Even playing with a piano, we won't play in equal temperament 100% of the time.
Not dissing this, it's a cool experiment and I like the visualization, but there's a reason strict just intonation hasn't been used for 500 years.