The adhesive used to hold the magnets in place is engineered to release cleanly and easily even after years of installation. It is a product manufactured by 3M. We have went through exhaustive testing to ensure it releases from different woods and it works as intended. After installation the support can be removed easily and the adhesive holds the magnets securely in place. A benefit of this design is that the support will 'find' the proper location each time it is placed on the instrument ensuring fast and consistent setup.
The weight and size of the magnets is so small and they are placed in a relatively inert part of instrument (the sides) so they will not have any appreciable effect on the sound. In fact, my magnetic armrests use similar magnets and one of the purposes is to improve the sound.
Sorry, I just realized I unintentionally hijacked the thread. If people are interested I will start a new thread and answer any questions there. My apologies