The Council of Saturn

[Infinite]

Question, would a STO master harvest themselves?
Usually they'd want to stay back and serve and then die naturally.

As Ra said, they don't cess the incarnation immediately after penetrate intelligent infinity. But remains incarnated to serve others. After the death of chemical 3D body, they will act from time/space fields of Earth to serve others.

The opening of the crown center takes place in flashes. It is a time when one's body opens for the soul to merge with the absolute. Most practitioners decide to continue to live until their allotted time on earth is finished. They want to impart the knowledge they have gained to others. This could be for two reasons: either they love everyone unconditionally and want to help them achieve liberation, or  they do not want to leave any reason for returning to earth in further incarnations.

Source: "The Kundalini Book of Living and Dying Gateways to Higher Consciousness" by Ravindra Kumar.