First, the Independent Sacramental Movement seems to be rife with imposter syndrome. Frequently on sites I see not only explanations of how, really, their sacraments are valid, but even entire pages documenting their lines of apostolic succession. I suppose that to some extent this is necessary to persuade Roman Catholics and others who might be on the fence about joining. Having been raised Roman Catholic I can say that I grew up knowing very well the boundaries of the church and less well the contents of the Bible. So it's not out of the question that the average lay Catholic would want some assurance that they were getting themselves into something 'valid.'
At the same time, I've listened to enough ISM podcasts to know that their clergy do often feel as though they have to prove something. The sense I get is that they consciously or unconsciously uphold the Roman Catholic Church as a sort of standard by which they will be judged. I don't think they should do that.
ISM jurisdictions should be able to stand on their own merits. If they believe that their documented lines of succession are valid, they can certainly share them, but they should also avoid trying to justify them. If the belief is that once a bishop, always a bishop, then run with that. Set that as fundamental and only revisit it to restate it, not to justify it.
Second, the ISM is extremely decentralized. There are multiple jurisdictions as well as countless one-off parishes making a go of it. there have been and continue to be attempts to pull some of them together, but the results are mixed. This could be seen as a real weakness, but then why don't we judge the Protestant denominations by the same metric? There are thousands of Protestant denominations and who knows how many independent congregations. There are even "undenominations" like the independent Christian Churches/Churches of Christ that refuse to organize beyond Bible Colleges and Christian Service Camps. Some denominations are in cooperative arrangments and others are far from it. Such is organized religion in a secular democracy. Accountability is raised as a point of concern in this context, but again I'd have to point back at the Protestants and say that they have the same issues. This isn't unique to the ISM.
One problem that does come from the decentralized state of the ISM is that it can be very hard for an adherent to find a new parish when they move. If, for instance, someone with an Ecumenical Catholic Communion (ECC) parish in Arkansas were to move to Connecticut (for some reason), they would find that there is no ECC parish for them. Fortunately, there is now a list of ISM parishes that is in development that could help them out, showing that there is in fact a parish of the American National Catholic Church in Connecticut. This would be compatible with their faith and practice just as well, I would think, as an ECC parish.
Independent Catholic Eucharistic Communities is a useful directory of ISM parishes around the world, including the United States. Keep in mind that, as I've already said, it's a work in progress.
My sense is that the ISM is maturing, to some degree. I'll be interested to see if that really is the case, and what comes of it in years ahead.
