He re-assesess his AI package every few seconds to make his quest progress correctly. Before they made the change, he would skip it entirely.
Yes, this is true. However, when the quest script checks the various conditions and determines that Boone
doesn't need to change his current AI package, the script calls "EVP",
which makes him temporarily exit his AI package and then restart it. This is why he keeps reholstering his weapon every 5 seconds while in combat.
Take out those EVPs and the script does exactly what it was designed to, except
without neutering Boone's ability to do anything.