In the Episcopal church (and really, Anglican churches in general), one is smply overall a member of the parish. (I speak from experience.) What happens outside the parish is rarely noted, except on the really rare occasions that it intrudes on parish life with things such as a new, revised prayer book.
One might hear of strange, odd things, such as the first woman bishop (unqualified, no pastoral experience, but she's black & female), but even these don't really intrude on your parish life, they're vague and far away. Things go on as they always have, and the infrequent changes tend to be small. One accomodates them -- there tends to be nothing to drive you away, unless you are looking for it.
Or you encounter a trigger.
As I did, in my first, last and only ECUSA diocesan convention. I saw what reigned outside my parish -- and left.
Amazingly John Wesley could have told you all about it.
No they do affect you, because the next batch of Pastors/Ministors you are going to have to interview for your parish are going to be trained and educated by the principles of that far away group has endorced...
That's the problem, you may believe your parish is immune, but its only a matter of time, and by the time these local churches wake up to do anything about it, it's too late.. the inmates are already running the assylum