Try holding a magnet near your tv. I'm not sure the screen on the Powervision has the same type of resistances towards magnetism as your moto Z, but like I said I could just be erring on the side of caution so as to prevent that sort of potential hiccup. I have no proof that it will or would do anything at all, but I wouldn't want to be the one to find out.
You must have a very old TV. That problem went away with CRT electronics. As said, the old tape drives, floppy disk, cassette and 8 track tapes were indeed susceptible to being damaged by magnets. No modern handheld electronic device uses that technology with the possible exception of some of the Ipods using hard drives. Everything else uses solid state memory / screens.
Installed today and seems real sturdy. Road to work and didn't see any issues. Magnet is real powerful and can't be pulled off has to be slid off. Only way my phone will come out is if it falls out of the case somehow.