Let me weigh in with a point here that takes two more for background [please note: I never used a breaching choke because of what I am about to say]...
Background 1: When using a shotgun to "breach" a lock the idea is to shoot downward onto the lock at very close range, sometimes with "breaching" rounds (dense powder in a enclosed shot cup), and usually down onto a padlock (
see Box-O-Truth here). At times if you are "breaching" you may need to be very, very close to do the "breach" you require, maybe even the muzzle touching something like a deadbolt in the door. Or maybe in the adrenalin rush of breaching a door an improper technique is used by jamming the door knob into the muzzle. However, discharging a shotgun with the muzzle basically "obstructed" by the door lock, the door handle or the door itself is bad. The breaching choke is designed to give space and ports to prevent someone from jamming an obstruction into the barrel (aka, the lock) and making a very bad day for them.
Background 2: When using ported chokes like the Primos and Patternmaster ones there is a great deal of effort put into ensuring the tubes are flawlessly parallel to the threads and the ports are flawlessly symmetrical in the gasses they put out ("flawlessly" being as best as technology can do at reasonable price). If they don't the pattern shifts either from being forced to one side by being unparallel or by venting too much gas in one direction.
Which leads me to the point: breaching chokes are designed to be used in shotguns that are either point blank onto a door or tactically to sweep small rooms. If your pattern is shifting at the 25 or 50 yards as you say it just might be in the tolerances of the choke design. This could be due to a bad parallel tolerance (choke is shooting to one side), unequal porting (gasses pushing the slug) or because the breacher choke is likely doing the choke in a shorter than normal part inside the barrel (the ported area does no "choking" unlike a ported goose/turkey choke).
TL;DR: OP's concern could be a manufacturing concern, or more likely IMO a design flaw of all breaching chokes and this one has that flaw worse than normal.
