Expressflight talks about Luton. Seems to me that airport has quite a few more feet of grass at the end of the runway regardless of the RESA figure.
Now if you were talking about LTN having a very short RESA (only the ICAO minimum)
Didn't an excecutive jet come off the end of Luton's 7,086ft runway a couple of years ago? Wouldn't have been a problem at Stansted but would have been bad news if it had landed at Southend and hit the railway.