And if you want to argue that he's a good overall candidate then fine, but when people talk about him it's almost exclusively for his offensive scheme and if your only reason for looking at a HC is the scheme on one side of the ball then I don't think that's a good way to look at hiring a head coach.
My biggest concern is staff building. I don't know how true the speculation that he wants to bring his staff full over is, but if it's true then that's a huge red flag because he should, wherever he goes, look to upgrade his staff. Even if that rumor is completely untrue, there is a worry to me about what kind of staff he'll put together due to no experience in a P5 conference and, seemingly, few crossed paths with P5 programs or staffs at all. Now it's not the be all, end all, as he's almost certainly crossed path at lower levels with coaches who have or will go on to be at the P5 level, and part of the AD's job is to help with that Batts should help with that.
The second thing I worry about is the defense which has been pedestrian at best at coastal. Not enough to usually cost them but bad enough to raise red flags here. IMO we cannot be a one sided program. It's not enough to have a good offensive scheme unless we either compliment with amazing recruiting on that side or, more realistically, we also have a good defensive side of the ball to go with it. Now, in theory he could address this with hires in the defensive staff, but that leads us back to point one.
Lastly, since the major selling point of him is his offense, and the recent success, it does lead to the question of how will that perform without McCall. Maybe his offense is the only reason McCall looks good. Maybe McCall is the only reason his offense looks special. I think it's probably somewhere in between where McCall is a great fit for a good offense, but without him Coastal is likely a 8-9 win team rather than 11 win the past few years. This is more of a ? than a red flag as even if it's the case then it could still be addressed just by good recruiting.
Chadwell would be a good hire, but he isn't the obvious homerun that people think he is.