Forget what you THINK is best
Gonzo
Your procedures are exactly what I got on my last refresher, one rule needs to be applied and written down to avoid Pilot Interpretation and therefore as many different GA's as pilots.
Rainboe I shall sincerely bow to your experience and admit that your actions on any given day AT HEATHROW would no doubt be safer and what you are saying is no doubt correct about the safety aspects but there needs to be a common denominator for all operators and airport.
Which brings me back to my original post, the parallel runway was a red herring......... circle, swingover, sidestep call it what you want -fly the original missed. ATC will know what you are planning to do and issue instructions before you get anywhere near the published procedure for the original runway