The real problem, imho, is lumping
electronics onto a torodial coil. While most electricians can discern ohms & kichoffs laws ,we are not trained in the
intricacies of electronica , cpu's, etc.
Conversely , methinks it could be universally agreed any given sensitive electronica installed across mains of nefarious
swells, sags & spikes may have less a life span and/or assume woes the ave spark is unable to pinpoint.
The notion of exactly just what the test button
tests becomes something of a mystery ,if not a frustration here.
UL ,in their ever lofty goal to save us from ourselves, has moved from a lock out feature , onto a self test feature
Go Here if you're so inspired , but don't expect specifics.
~S~