Something nice about the American National Catholic Church is that it uses the familiar 2nd edition Novus Ordo mass. This is a descendent of the original Novus Ordo mass that came as a result of the 2nd Vatican Council, and is familiar to everyone from Boomers to Gen X. Even for Millennials and Gen Z it is close enough to the 3rd edition for them to adapt, though they might stumble here or there with some wording.
Other jurisdictions of the Independent Sacramental Movement use a wide variety of liturgies, depending on what they've adopted and adapted for use in their churches. Some lean East, using St. John Chrysostom's Divine Liturgy, or a variation on it. Others lean West and draw from the Roman Church's liturgy. It is also true that some ISM jurisdictions are quite conservative and may use the old Latin mass of the Roman Catholic Church.
By using the Novus Ordo 2nd edition, Roman Catholics who are familiar with the liturgy have little or no trouble following along and participating. I can only wonder how churches using another form of liturgy manage. Perhaps they print out the full service each week, as the Episcopal and ELCA churches tend to do.
In the end, the ANCC's consistent use of the familiar Novus Ordo 2nd edition mass builds a bridge for Roman Catholics to join in, and puts everyone on the same page (literally) regarding the liturgy. This emphasizes the truth that mass isn't just about rules and rubrics, but more so about belonging.
