>>3813054https://fotodioxpro.com/products/fd-eos-pro-fc10>Focus Confirmation Chips do not support Canon EOS film cameras and should neverbe mounted to a film camera as this may result in short circuiting the film camera system
(film cameras use older electronics that do not support this function)
What makes you think a similar thing can't happen with modern cameras? Maybe you have a few lenses with smart adapters, upgrade your body and suddenly something gets fried.