Replacing a bad circuit breaker (housing was cracked at factory install). I was curious if there is a reason that the feed from the battery is on the AUX post and the feed going to the converter on the BATT post.
It really doesn't make much difference one way or the other, except the contacts inside the breaker are optimized to interrupt current flowing in one direction better than the other (less arcing across the contacts).
Normally current flows from the battery to the load. If this breaker is on the output of a converter charging the battery, the current flows in the opposite direction from the converter into the battery. Thus the "backwards" orientation.