It doesn't matter whether the aircraft's at max landing weight, near to it, or over it.
It doesn't matter whether the aircraft is a Public Transport flight or not.
You don't ask ANYONE to orbit on final. It's appalling controlling technique and the ATCO concerned should be taken out and given a good kicking! So he's got one to get away - If the gap's that small that he asks someone to orbit, then it's small enough that another 30 seconds on the ground isn't going to hurt.
Have we not learnt anything from Southend and the configuration of aircraft?