That's interesting Mr Red about 'saft' meaning foolish or daft.
Here in Norfolk the same word is used to mean exactly the same thing, only pronounced more like 'saaaarft'.
Dahn Sath (nearer to London) if someone is 'soft' it can mean they are soft-hearted or kindly. Or daft.
My (very) Norfolk neighbour will often say "Dornt yew be ser saaarft yew fewl!" if I offer to pay her for her gorgeous home-grown tomatoes which she lets us have at around this time of year.