Had a "one to one" discussion on this very thing with an inspector from the CAA a couple of months ago.
A local ATC were getting p****d off by IMC students suddenly doing the go araound at almost two miles out - screwed up their plans for the aircraft behind.....and the guy ahead in the training system who is usually turning back to have another go.
CAA man said, quite categorically, that the 500/600 is RECOMMENDED not mandatory - and continued approach to plate minima is perfectly acceptable.
Personally, I disagree - and always went with the 500/600 idea.
BTW - Simjock....when you do your forthcoming exam, try not to use the phrase
Precision Approach - Plate MDH + 200 + 50 PEC or 500ft aal whichever is greater
A precision approach does not have an MDH.