I should have been more clear on what I wrote about the priest + people dialogues at Mass.
The Lord be with you
And also with you
This frequent one and the other more extended ones for the introductory rites and just before the Preface and Sanctus are what we’re talking about.
My scholarly colleagues regard the singing of these as among the part of the Mass with the highest importance for singing. While a good singing priest makes this easy, my doubts are not that they shouldn’t be sung. I question their relative importance in the spectrum of musical worship.
Hymns like the Gloria or Sanctus, litanies like the Kyrie or Agnus Dei, acclamations like the Mysterium Fidei or Alleluia, and the psalms all rate higher in my mind because their texts directly address God and serve as a direct act of worship.
The dialogues do not.
Because of that, I would not rank them as having similar importance with the aforementioned liturgical items. They serve as conversations in the presence of God, and as such, I don’t see why they wouldn’t be given a lower status among the various responses at liturgy.
Sing them? Sure. Whenever the priest will do it.