Welcome,
Yes, nearly all of the properties of OEPocketsphinxController refer to pocketsphinx startup values or initialization values for the audio driver, so they don’t get recalculated by pocketsphinx or OpenEars’ audio driver on the fly. On the other hand, the public methods of OEPocketsphinxController refer to operations that OpenEars can make on an already-started instance of pocketsphinx, so they are for the most part expected to be called on an already-started listening session (like suspending or changing a model or grammar).
A lot of attention has been paid to speeding up stopping and starting times in OEPocketsphinxController, so you may find on modern devices that there isn’t as much of a speed penalty to stopping and starting with new values as you may be concerned about, give it a look.
It would be helpful to share your technique for objectively evaluating the level of background noise – if it is accurate an automatic vad adjustment could be added to the framework.