Newby, that's great to hear!! I'm glad you've got something figured out for him.
AQHSam, the only way I can figure a roller bit would be harsher is if you are talking curb bits. Often, the roller on a curb bit is inside the port and that reduces the tongue relief a port offers. That, for some horses, makes it harsher, especially if they have a fat tongue or don't like tongue pressure (or are not properly prepared to carry a bit with no port). If the bit has a jointed mouth like a snaffle, then I don't see how rollers would make it harsher.
However, IME, whenever a horse is fighting to get their tongue over the bit and the initial cause has been taken care of, the only way to get them to stop is to put them in a bit where it is impossible for them to get their tongue over it; like a ported bit.
I rode a pony that was that way, he would fight with the snaffle constantly to get his tongue over it and then fight to get it back under, then start all over again. He was never quiet with a regular snaffle so I swapped it with a ported bit that had a solid mouth and about 5 minutes later, he was quiet and happy as could be.