Not gonna lie, I'd never heard of an EPQ before (I'm kinda old), so I had to look it up.
So no I've never done an EPQ, but it looks super interesting. Do you have to write an essay on whatever topic you're interested in - so you do your own research and so on? I'd absolutely love that!
I watched this really interesting online lecture the other day (it was an Eventbrite event) - it was on "How to fight and die like a Greek woman". They went on about different ways women stereotypically committed murder in ancient Greek times (poison, throwing roof tiles off roofs), and explored this theme within eastern women vs traditional "housewife type" Athenian women, and then delved into the Amazons, and then looked at other ancient women famous for being actual warriors and their military positions.
It was a really good lecture.
If you're interested in women in the ancient world, it was a really intriguing angle to learn about, so there's an idea for you.