As per the tooltip, attack pattern omega is supposed to provide immunity to movement debuffs. I've noticed though that it has no effect on graviton pulse. Graviton pulse would seem to be a movement debuff, so is this a bug?
I have heard more than one escort pilot complaining that APO doesn't counter grav pulse. Whether this is a bug or intended I don't know, but it pisses said escort pilots off pretty bad sometimes, hehe.