ie Aircraft not insured for training, or only insured for the owner to be PIC.
I think all the policies for SEP a/c I've ever seen have a clause covering an instructor, as well as maintenance personnel, can't see what benefit financially there'd be in excluding instructional flight.
The problem comes when owners ask an instructor to ferry their a/c for them, this is NOT covered as above as when solo, one is not an instructor. I've been an additional named pilot on several a/c so that I can assist the owners. There has never been any difficulty or additional premium for this and it washes away any 'grey areas'.
TOO