Google 'Phillip Carter' if you want to find out the results of these sorts of approaches.
I was amazed when I met pilots who were willing to fly these 'Standard GPS' approaches into unapproved sites or airfields without instrument approaches. It was clear that pilots routinely fly down through 300 ft even in the London area, because 'that is the only option'. Obviously, there approaches are practiced and checked out in good VMC first, but it won't take account of any cranes being erected etc.
I did ask what ATC comment was made if they descend IMC, and the reply was that ATC aren't necessarily aware - You just report descending, continuing VFR, QSY - So the onus is on the pilot and ATC have no clear reason to question you.
I am aware that I sit here in my ivory tower, safe in the protection of a large commercial operator and I have none of the pressure bearing down on me that a small charter company would have. Even still ........... !