I've only ever asked the cabin crew to pass a message to the flight deck once.
As a PPL for 26 years, I was on an AC regional jet at CYQT last February. We had been de-iced, but kept waiting on the deck due to a backlog of a/c waiting to depart.
During the next 25 mins, heavy snowfall had continued and led to a visible snow build-up on the wings and control surfaces. When the Capt announced we were pushing back, I asked the cabin crew to let the flight deck crew know of the snow build-up situation and that the message was from a PPL.
To their credit there was an immediate announcement that we were going to be de-iced again.
It 'cost' us 10 mins.
Was I being overly concerned? Maybe, but I would not personally have departed in that condition. My view was that it's my neck on the chopping block too.
Better 10 mins too late in this life than 10 mins too early in the next.