I don't see why a no hub would be an issue particularly in a vent line. No hubs are used all over the place in home repairs including underground. Now, I guess one would consider vibration in an RV, and I guess over time that could be an issue. Otherwise, you will need to find you an ABS slip coupling to do what you are needing to do. I would assume you are dealing with 1 1/2 inch line. You would need to go to a plumbing supply to locate an ABS coupling.
2016 Wildwood 195BH
2009 Silverado 1500