Why would an IP assignment have a negative career impact?
First assignment IP, is not a Major Weapon System tour (frontline aircraft). When you do get to your MWS after that first tour, you’re behind your peers in qualification/experience in that system and have a steeper hill to climb, so to speak, to reach those quals that make you competitive to promote and/or screen for leadership opportunities. Hence why it’s more “career proper” to do an IP job post-first or second operational MWS tour. However, as needs of the service drive everything as well as timing, one may not always have the choice in that.