I get that - but clearly 'the system' has decided that this does not constitute a safety issue (ie nail scissors are considered a greater risk).
Have you tried to change policy and have phones removed from SLF before flights? If not, perhaps it's not that big a deal - and if it is a big deal, why not try to make this change?
Sorry, throwing petrol on the fire, I know...
Cheers, Sam (heading for bunker, with helmet on head).
PS for what it's worth I switch my phone off because I know about the annoying noise it can make when looking for a signal.