In the hands of a competent player, these upper notes are not especially loud or shrill.
Because of the repeated upper notes, the focus moves to the inner voices.
There are problems with the upper notes, starting at about E flat, which lose focus and poise in the opening aria.
Some of the upper notes required more intense concentration, but they were well managed.
Here there is no contradiction, because the bass is consonant with all the upper notes.
A band of sound begins, and the upper notes descend until only the nucleus is left at the bottom:
His voice had rather high upper notes, and very resonant middle notes.
He occasionally had trouble supporting his upper notes.
Out of the upper note a second, lower note should come out simultaneously.
His upper notes these days are at risk, but he attacks them decisively, turning a vocal struggle into a musical one.