The plug on the Ballistic does pull out, but I have no idea how thick the case is.
I'm actually more worried about the extra thick bumpers on that case hitting the bottom of the Seidio causing it to raise too far away from the Dock. If it did...it definitely wouldn;t work. Either way, the most important thing (for me at least) is that it works with the UAG. The Ballistic I'm just going to purchase for a weekend outdoors and trips types of thing.
Let me grab you a link from another thread really quick.
It has better photos of the Ballistic Case and ports.