The Undeground Jubilee bass bin wasn't patented, so that would be zero sued on the Jube Bass Bin Clones. Jubilee with a drone did implicate a patent, and Pannacea Engineering was hit with a cease and desist letter when he posted on his website he was planning to make and market a drone version of the Jubilee bass bin. He walked that back extremely quickly (on this Forum no less) It doesn't take a lawsuit typically after getting a cease and desist from a patent/trademark litigation firm.
To your point, if an infringer never tells another living soul that they have duplicated a patented product, and it never sees the light of day outside a residence, and even then the patented item sits behind a grille, etc. the patent holder is never going to know, there will never be a need to send them a C&D, or serve them with a lawsuit.
Surprisingly, though, people who are wired to go to the effort to copy a patented product are just not wired in a way that they can be content with the satisfaction of the improved sound, picture, or whatever it is. They are compelled to share there creation with the whole world. I have seen it over and over on this forum, and other forums as well.