It's not something thats all that well publicised, I agree. Also limited to 3 hours after your supposed arrival. I suppose after that EU-261 should kick-in.
https://www.tpexpress.co.uk/special-...hester-airport
I suppose its unlikely that your flight would be so early as to make getting an earlier train of much use, other than transatlantic flights in the winter, when tailwinds can be strong?