if you did carry out a perfectly legal PFL in most of the UK down to 1' you would likely be guilty of "recklessly or negligently acting in a manner likely to endanger an aircraft or any person in an aircraft"
Really? Why?
I'd expect to be able to safely land if I had to. After all the engine might not pick up when you wanted to climb away. A PFL shouldn't be dangerous. In the early days of flying microlights it was common practice to actually land off a pfl and then take off again (sadly no longer allowed as its necessary to have the landowners permission).
I would further add that if you've only ever done a PFL down to 500' agl, then you've never done a PFL. The final 500' can be most instructive. I suggest you ask an instructor to show you.