Since the same dynamic I've seen so very many times before is playing out yet again, I see no reason to waste any more time in this thread.
I have decades of experience solving engineering puzzles far more complicated than this one, and I am quite sure that job one has to be measuring the existing noise before proceeding with any further effort toward mitigating it.
Let me know when or if you would be able to test some additional materials.
I do believe that while "roof patch" is not in the same league as coatings and sheet dampening materials, I would be so sure that is true of all building materials.
Based on the vociferous nature of the SS rep's reply, my guess that their Spectrum product might be not much more than a liquid-applied Acrylic roof membrane with limestone or silica added might just have hit a little too close to home.