What became of him after the coaching shuffle down at South Carolina? Was he retained by Muschamp or let go? If the latter and if he hasn't already been picked up by someone else, he sure would be a mighty fine choice for QB coach at UK if we could make room for him.
I had the opportunity to speak at length with Coach Mangus on several occasions and he was one of the most impressive coaches I've ever met in person. He talked to me about his recruitment of Connor Shaw, and what many people don't know is that when he was recruiting Shaw's older brother Jaybo (Mangus was the OC at MTSU at the time), he already had identified Connor as a future star. When Shaw's father (a HS coach himself) asked him about young Connor, he replied, "I'm going to have to have a much bigger job before I'm able to recruit Connor."
So a couple years later, Shaw's dad gets a phone call from Mangus, and coach reminded him of that conversation. "Well, I'm calling to tell you he has a scholarship offer from the University of South Carolina." Connor was pretty much a done deal from the start, and Mangus developed him into the best-performing QB in school history, including an undefeated record at home as a starter.
Mangus was also the one who got South Carolina in the game with Barker right to the end, and he's the one who developed the relationship necessary to solidify Brandon McIlwain to Carolina as well. That relationship was so strong that Penn State tried playing footsie with Mangus, dangling the possibility of an OC position in front of him, but nothing came of that. Anyway, Mangus was also prone to taking some big risks on players from his preferred recruiting territory, rather than going for much surer prospects close to home--so that's something you would need to watch for if he ever came to coach at UK for Stoops.
As for Junior, he is among the most hated figures ever at South Carolina, but I feel comfortable predicting he will not run into that kind of trouble at UK because the same factors just aren't present. Spurrier had more or less handed the reigns to him a few years back and allowed him to do a lot of the running of the program, which was disastrous on a lot of fronts, but not least because it fractured the staff. He was given the RC position which had been informally promised to somebody else who was actually a great fit for that job, who subsequently left the program. He was an abominable recruiter in general and hated the idea of kissing up to HS coaches and players. Recruiting meetings would only take place when he was in the mood, and the talent level visibly crumbled on his watch.
All that said, don't listen to the bitter South Carolina posters who say he can't coach the position. That's provably untrue. He developed Kenny McKinley, a HS QB who was a very raw player, into one of the smoothest and most productive WRs in school history. He coached up guys like Tori Gurley who were really just big bodies into extremely reliable receivers (Gurley had zero drops his junior season). Even middling talents like Nick Jones (a HS teammate of Marcus Lattimore) ended up being very good under Junior.
Now, his personality sucks and the players hated him almost as much as the fans, and moreover, he plays favorites. But with that to one side, I can assure you that the UK receivers will be a very solid group in the run-blocking department (he won't play guys who can't man up and block), as well as in the dependability department (God help you if you drop the ball while he's watching, no matter who you are). He teaches footwork extremely well, and while WR is very much a talent-driven position--some guys have it and some don't--he'll give you the most you can hope to get out of the talent you have on hand.