They do say 13.6 or lower for float.
They also say the balancing needs 14 or more.
They say this too:
--If you are cycling power in and out of the batteries when plugged into shore power with your 14.6 volt converter, it is completely acceptable and will not cause any issues. If you are plugged into shore power when NOT cycling power in and out of the batteries(such as in a storage scenario) for more than 3 weeks at a time, then we recommend disconnecting the converter. --
However that makes no sense, since on shore power the converter will do all the work and the batteries will not cycle at all. Howinheck is that any different from being on shore power and the RV in storage when they do not want you to trickle charge (assuming that is different from floating with the batts full)?
They do not mind 14plus all day on solar since that drops when it gets dark every day.
So it is all a muddle, but the comments give a general picture sort of. Seems if you do have these batteries, you might need to get a clarification for your exact situation.