Please post the UK rule that says you are relieved of "see and avoid" responsibilities (i.e., can fly "head down" so you can legally meet the Simulated Instrument Time requirements) when flying solo IFR and VMC.
As has already been posted, if you are flying simulated dial time in VMC you need a safety pilot. If you are actually in IMC then you don't, as it's not simulated. It seems counter intuitive; if the weather is brilliant you need to drag someone along with you to shoot a few approaches, if the ducks are walking you can go on your own.
In my logbook (I'm not a commercial pilot by the way) the two columns are 'Instrument Flying' and 'Simulated Instrument Flying'.