Jöns Aschan does a balance brace in his Fragrance low volume kayak and a greenland style paddle (GP).
Greenland style paddles and low volume kayaks gives some benefits in training rolling techniques. The paddle can be built to have more boyancy than the euro paddle. The boyancy is equal to the weight of the water displaced by the volume of the paddle, less the weight of the paddle. If it displaces 5 litres of water and the paddle weights 1kg, then the lift would be equal to 4kg or 40Newton.
The low volume of the Fragrance kayak with the small and relatively round cockpit has some advantages. The round shape of the cockpit rim gives a tighter fit of the spraydeck and less of water leak while rolling. Water is still likely to leak in along your waist, wrists and neck - unless you wear a tuilik. The low volume implicates a low front and backdeck giving more free space to move in while rolling using a variation of techniques.
The maximum of body volume that is outside of the kayak inner rim is kept in the water, while the maximum of body weight is kept away and on the offside of the inner rim. Flexibility and good kontact with the seat, kneebraces ("Masik" in Skin on Frame kayaks) and footrests is important.