Vatican II addresses lay liturgical ministry:
Servers, lectors, commentators, and members of the choir also exercise a genuine liturgical function. They ought, therefore, to discharge their office with the sincere piety and decorum demanded by so exalted a ministry and rightly expected of them by God’s people.
The dignity is demanded not just for their office, but for their stature as believers.
Consequently they must all be deeply imbued with the spirit of the liturgy, each in (their) own measure, and they must be trained to perform their functions in a correct and orderly manner.
There you have it in print: the importance of liturgical formation, and the execution of their service by the rubrics, but also in accord with local demands on their function.