The point came up earlier about whether blacking up could ever be taken to be a representation of a non-white person; by implication it couldn't and therefore wasn't deemed offensive. A moot point, given the history.
What about mummers, since the Philadelphia Mummers have been mentioned? In England the Turkish Knight/Egyptian whatever is invariably blacked up and dressed up and called Turkish, Black etc., and is definitely a Muslim, the baddie, and slain in public in front of child spectators for not being Christian!
There seems little ambiguity there, little scope for changing the plot, yet would anyone wish to see it die out?
Perhaps the difference has been the relationship with Islam as a more or less equal and worthy adversary in the past, quite different from our despicable treatment of black slaves. But our relationship with the world of Islam is changing fast and becoming more local.
Most muslims in the UK occupy an inferior and menial role, as do most blacks (quite far removed from the "taking over" position described in the press) and may come to resent "negative" representations more than they seem to at present; and it would be quite hard to defend most mumming by claiming that it is merely disguise, as in "Guisers".
I think it is almost impossible to formulate a firm principle upon which to stand and defend any sort of traditional ceremony, other than to say that potential offense is not the same as actual offense. What would happen to a traditional mumming ceremony that always performed in the same spot, if that same spot eventually only attracted an audience of small muslim kids? They would have some thinking to do depending on the kid's reactions, and no offense might be given or taken.
But at what point does it start to resemble Orange Order parades insisting on their right to parade through Drumcree because it's traditional and they have a democratic right to cause offense?
I hope I can cause offense if I wish, but I don't always wish to. Every performance is a unique event. I would not like to see the end of mumming plays; if no offense is taken then no harm is done, but if it begins to leave a bad taste in the mouths of the performers then it will not be repeated and it will evolve or die out.
In the meantime, where the plot does not make it essential to potentially cause offense, and it would seem that Border Morris comes into this category, why not do as these dancers in the background
have done?