I played with ankle weights in my early dry dives. Once I realized that I could set my DUI harness a few inches lower than my natural hips I moves the weight into the harness and my kegs were fine. YMMV but I'm in a neoprene drysuit with big honking boots and thick socks so I'm not lacking foot buoyancy. The more you can reduce that leg mass in motion the better.
Pete
Pete