My understanding is that you should only fly one burgee at any time and that is of the local club to which you belong or whos function you are attending. So this is at the masthead or stbd crosstree if masthead full of electronics. If flying a courtey ensign then I think the burgee should go to Port.
Mizzen mast is an appropriate place for the ensign but I cannot say I have ever seen a burgee there?
I know when I go abroad next week the RNSA burgee will be at the masthead and undefaced blue at the stern, courtesy ensign at stbd crosstree and Forum burgee (not a 'Club') at port.
I like tradition and am quite happy to follow etiquette.