Jansenists, strictest of the strict, promoted liturgical reform a la Vatican 2 . . .

A blast from the past, or back to the 18th century . . .

. . . according to a "non-Tridentine [non-Trent] model," say scholars who researched Jansenist liturgical reform. (As cited by Brian Van Hove, S.J. in the American Benedictine Review, "Jansenism and Liturgical Reform," in 1993.)

Who tells of an American, F. Ellen Weaver, who noted 18th-century innovations which are remarkably familiar to us today:

. . . introduction of the vernacular, a greater role for laity in worship, active participation by all, recovery of the notion of the eucharistic meal and the community, communion under both kinds, emphasis on biblical and also patristic formation, clearer preaching and teaching, less cluttered calendars and fewer devotions which might distract from the centrality of the Eucharist.

Even the "kiss of peace" was practiced at [Jansenist center] Port-Royal, and a sort of offertory procession was found there and elsewhere among Jansenist liturgical reformers.

Their liturgy was to serve the reform which they had in mind. Prayer would be a way to teach, lex docendi, lex orandi — roughly “as you are taught, so shall you pray,” a switch on the venerable lex orandi, lex credendi, “as you pray, so shall you believe.” Jansenists would use liturgy to change how people thought — what they believed —and how they prayed.

Weaver:

Inside the parish church the service must be made congregational. And here doctrine entered.

Specifically,

The liturgy was not an act done by priest for the people, it was 'a common act of priest and people'. Therefore all the liturgy, even the prayer of consecration which was [customarily] said secretly, should be said in a loud voice, and the congregation was to be encouraged to share.

A communal act of consecration?

Not quite. The Port-Royal leaders "plainly" believed that, but they knew it would never be accepted by their people or "the Church at large," so "radical a departure" would it be "from hallowed tradition."

So they did the next best thing, calling for translations of the mass (missals) and reading of the gospel in the vernacular after the priest read it in Latin.

Which had become standard practice by mid-20th century, as some of us remember.