I think that people dressed in historical costume are a red herring the context of this thread.
They are (in my experience at least) at least supposed to be connected to the venue in some way, illustrating the history of the place. If individuals don’t feel that they learn from them they can avoid them. I quite like them, and my children were always delighted to see them, but they don’t foist themselves on people.
A visit to a stately home with no links to gay history is not likely to be enhanced by glittered-up tour guides. If, as is statistically likely, a previous owner was gay, out (less likely) and their sexuality has a ‘story’ attached, by all means have a reference to this in the guide book and teach the guides about it, but otherwise I just don’t see the point of fake campery.
Also, selecting one aspect of a person’s life to highlight is useless unless the other aspects are catered for too. If someone is gay, disabled and poor, their disability and poverty could exclude them from NT properties far more than their sexuality. NT prices are high, and by no means of them are accessible to people with various disabilities. It smacks of tokenism to concentrate on the aspect which costs virtually nothing to highlight, can be seen to be being done, and ignore the others, which may well have a much greater impact on the life of an individual.