Neither my kit-built nor ARC Vectors needed any trim tab. It would however be a simple matter to slice the outboard TE beyond the moveable flap and fit it with a hinge and adjustable link to a small horn on the trim tab. But I bet you won't need it.
If PJ is reading this, I flew the Red Vector 5 times today in our bitterly cold California winter (70 degrees F, light winds) and it still flies as good as ever. I need to be careful with it though between now and July. I should probably park it.