There's no dispute about crew training and required standards or the "radio announcement for wipers". The understanding reached on those topics is primarily thanks to your patience in explaining over and over again how the US elements link together. I guess the discussion about (A-)SMGCS has been quite fruitful as well.
Yet still, despite guarding your flank on all of the above, I find the attempted conclusion of your last post narrow-sighted.
If the procedures (on ATC side) were proper the controller would not have cleared the departing onto the runway. We haven't heard what the separation limits are for 1/2 SM departure ahead of a landing (I'd like to think 5NM for lining one up, resulting in 2NM (600 ft) being the latest expected moment (i.e.1.5 minutes later) when the departing plane should exit the LLZ signal cone by overflying the antenna), and what are the procedures to avoid an absent-minded person to breach any such limit. Obviously, this forum does not have the expertise/insight to discuss that. Just my note then, that limits are not procedures.
Borrowing yours:
“ Rain procedures are in effect, please turn on your windshield wipers, and open your umbrellas”
what we called (undisputedly ATC's) procedures is that after such broadcast everyone in the car must chant "wipers-on, umbrellas-up" out loud 3 times. Because under LVO we are required to a) be more conservative [limits] b) double down on the crosscheck [procedures].
Or better yet, let's ask the other direction around:
If, by an ugly play of the devil, the ATCO working the runway would have a brain tumour moment and line up a plane in front of landing traffic just short of 3NM....
... what are the
procedures in the UK to stop him from doing so?
(and while I trust 'oh that couldn't ever happen here', the point of the question is to hear why and how is that assured)