But in philippines CPL holders fly with PPL holders on Single pilot certificated airplanes and they both log and I don't know how they do it and if it is acceptable to their aviation authority but I have seen guys doing it. but then the funny part is even if you have a plane rating on your CPL but do not have it on your FI license you can not instruct on that despite it comes under same class and category.
I doubt very much that their doing it legally....
unless thay have some kind of 91.109 provision like the FAA.
To my knowledge the only authority which accepts safety pilot time is the FAA.