Balance in the V, throw the jabs.
Hold the V tight, if you wobble the abs aren't doing their job, slow the jabs.
Holding the V-sit keeps your abs under relentless isometric tension, and every cross-body jab adds a rotational pulse your obliques have to produce and then immediately cancel out. The dumbbells magnify each wobble, so your core is making corrections punch after punch. Use it when static holds have gone stale and you want stability and rotation trained in the same drill.
Very light, think warm-up weights. The V-sit and the rotation are doing the loading, and heavy bells just wreck the position and shift stress where you do not want it.
Yes, heels lightly on the floor is the sensible regression while you build the hold. Keep the lean back and the tall chest, then lift the feet once the jabs stop shaking you.
You have likely slumped into a rounded lower spine as the abs fatigue. Sit taller, shorten the sets, and end them the moment the position degrades rather than pushing through.
