Ryanair has been paying passengers' UK APD for ages. The airline has paid my UK APD (and more) countless times. I could get a list together but I'll simply cite a recent booking from memory: £4 return Stansted-Palma. I paid not a penny more.
Now, this was only possible because I used an Electron card, did not have hold baggage, did not take insurance etc., etc.
I see today (15 May) that similar trips to various destinations in Europe would be available at £6 return if I was interested.