No Problem as long as you approach at correct speed and aim to land on the threshold as you would normally. If you have not touched down by the mid point go around as a few weeks ago a PA32 ended up in the boundary fence quite badly damaged. Remember the airfield is closed on Sundays and there is no fuel available. It is available at Lands End. Give ATC Scillies a call as they require PPR and will give you a comprehensive briefing on the local procedures.