I'm amused at times when I hear the word "safety pilots". You mean a young, sometimes even no rated pilot sitting in the right seat playing the role of a co-pilot or first officer on an aircraft where there is only one pilot needed.
OK, safety is a blury word, but for me a non rated pilot is not an increase in safety per se. To the contrary, sometimes instruction situations may distract the only pilot from its official duties.
The word safety pilot comes from pilots with less experience on the left seat as pilot in command, who have a very experienced rated pilot on their right side as a support. That's a safety pilot.
Well, sorry to interrupt, continue...
Dani