you can't be IFR if you aren't carrying an IR holder.
and if you are carrying an IR holder (who is not an instructor) then
he has to log the IFR flight outside UK airspace, not you.
The common practice of carrying an IR holder in the RHS works on the idea that if there was an enquiry,
he would pretend to have been the PIC. And this needs to happen before you have logged the flight, otherwise you have to very quickly rip out the relevant page out of your logbook
