I don't have time to get to the bottom of this, this week anyhow, but the instances attached to the text authority https://hymnary.org/text/i_will_exalt_my_god_and_king_and_i seem to me to consist of two extremely divergent paraphrases, aside from the extol v. exalt difference between the most recent instances. Also, one of the closely related authorities, https://hymnary.org/text/i_will_extol_thee_o_my_god_and_praise_th, has a Christian Hymnary instance attached to it that looks to me quite too divergent to belong there.
Comments
Psalm 145
All of the instances of I will exalt my God and King/O Lord Thou art my God and King are the same paraphrase. The original first line in 1912 Psalter and the New Metrical Version of the Psalms (1909) (which preceded the 1912 Psalter) is “O Lord, Thou art my God and King.” “I will exalt my God and King" is altered from the original. An alteration does not warrant a new authority.
The Christian Hymnary version of “I will extol Thee, O my God” adds a refrain. The addition of a refrain also does not warrant a new authority.