I wouldn't know for the airbus. But in the 737 I drop the gear and flaps 15 at approx 5NM and wind the speed back at around 4.6
The gear must be down and locked at 1500ft AAL
You might see this on your screen as reducing early, but the 737 will still be doing 160 at 4NM maybe 5kts slower.
But remember we should be stable at a 1000ft AAL. Thats flap 30 or 40.