To answer the OP. I'm like
@ianrauk too. Sometimes I do, Sometimes I don't depends on how far up I can see, if I can see a safe and sensible drop in point, whether I'm just ambling along without time being a factor, how well I know the bit of road and prevailing driving etc. There is no one size fits all rule and common sense should be applied.
To add another wiggle into the mix, by preference I will filter on the right of traffic = motorbike like and on the drivers side so more likely to be looked out for (particularly in less cycle-y areas) and more likely to be seen in their peripheral view of their wing mirror.
I'm also more visible to the oncoming traffic e.g. if there's their right turns coming up so I'm not a last minute surprise if some helpful driver in my queue has flashed them on without checking around themselves properly.