Didn't JF make one in the early 90's ?You are only talking about labour efficiency.
What about financial efficiency?
Perhsps if land was declining back to £1000 per acre then spending half a mill on the shiniest ridiculous toy wont be quite so attractive.
For the smaller farmer a modernised trailed combine would make a lot of sense.
Kidd saw that 30yr ago but kv shut it down
Obviously never took off.
Quite fancy one for my eerrrrrmmm..........eerrrrrrr 40 acres.