There is probably a distinction to be made between 'Harrington Humps' to reduce excessive stepping distances at lightly-used rural stations without having to reconstruct the entire length and 'level boarding' points, as have become quite common at tube stations with lifts served by trains with wheelchair areas.
AIUI the Thameslink idea at St Pancras is more for a degree of level boarding rather than tackling an excessive stepping distance (which would be quite odd at a relatively new station).
Anecdote about Harrington Humps:
I was on a Cambrian Coast train, about to call at Aberdovey from Machynlleth, and noted a clearly infirm couple struggling to the end vestibule of the 158. Knowing that the station had a new hump I redirected them to the centre doors and shifted their luggage for them. On arrival at Aberdovey we duly stopped alongside the hump and I helped them off with their luggage. Many thanks all round. "This is a good idea, isn't it?"
The train disappeared off into the distance. "Oh, isn't this Tywyn?" Ah well, only a two-hour wait on a station with no facilities. Oops.