I feel your pain. Most of the time you would be fine but there is still a chance that you could have problems with the letter of the law.
I find a lot of knives that I like that are just over 5.5" and I have to pass on them. I've found some possibilities though and the Ratmandu seemed like one of the best. Bark River Bravo 1.25 was another, and Bark River has some others in the reasonable size range. TOPS has a few, there is the Becker BK2 or the ESEE 5. The ESEE Laser Strike is similar length but lighter. I don't know any that have a fuller though. I like to contribute to the arguments about a fuller since I know what it won't do, but this is the first time I've known of someone using it to enhance their grip.
I find a lot of knives that I like that are just over 5.5" and I have to pass on them. I've found some possibilities though and the Ratmandu seemed like one of the best. Bark River Bravo 1.25 was another, and Bark River has some others in the reasonable size range. TOPS has a few, there is the Becker BK2 or the ESEE 5. The ESEE Laser Strike is similar length but lighter. I don't know any that have a fuller though. I like to contribute to the arguments about a fuller since I know what it won't do, but this is the first time I've known of someone using it to enhance their grip.