Hi Roy,
I think I would be inclined to move it into its own pot at some stage, remember that they like a high humus, lime free compost (Ericaceous).
I would just be worried about the Azalea not getting the correct watering.
At this stage it may well come out still showing the pot shape it was grown in.
To fill the space why not put in a primrose or polyanthus. Plenty around cheap and colourful.
Taffy