Yes, you can write the hours in your logbook, but, No, you cannot claim these hours for ratings or license issues. If it is only insurance, talk to them and ask wether they need PIC hours or accept such alternate training you receive. And further, No, you are not wasting time, independent of rating or license, as you learn to fly the beastie with your friend and that does much more real value than any piece of paper.
Yes.
And in particular:
you are not wasting time, independent of rating or license, as you learn to fly the beastie with your friend and that does much more real value than any piece of paper.