in 20 years living at the 26 end of Luton, I have seen a few late on to finals myself.
nothing worrying or anything like that but I do remember back in the early 80's a comet 4 turning onto finals at 2 miles and then once aligned up with 26, climbing !
Its like the ILS system picked up the center line and then climbed to get the right glide scope angle.
Still impressive.
These days I see a few sleazy jets turning onto finals at 2 miles so its not that unusual any more.