Do Loons really use those claims?
Claims 5 and 6 describe (as Marin Gregorie points out) 18th century tech. By the late 19th century altitude control (at least for trim) could be handled by the partial inflation of ballonets inside the larger main balloon.
If a Loon is going to be up there for a while, and "navigating" by changing altitude to catch wind from a different direction, an altitude control method that relies on using up a finite supply of lifting gas and ballast is going to lose badly to a method that only requires a compressor or the like, driven by the same power sourse as the RF gear. Sure, they would use release of lift gas for final descent or in emergency, but since that method is over 200 years old (as opposed to merely 140 or so), it is unlikely to still be patented, even in the U.S.