We've travelled quite a bit with our boats and never had any trouble with the sytem we devised. Courtesy flag at top stbd halyard. Decent gap between that and RNLI flag, then original PBO Magazine flag. Port halyard we have the Club flag then regatta or other event flag. Masthead we leave clear to allow VHF and windex to be free to work. We decided on this based on seeing Merchant ships with flags on cross-tree halyards and ensign at aft staff. You never see a burgee / house flag or other at masthead of any ship.
-------------------- Some of us Ladies may surprise you.... Wife of Refueler