Are there any modications to reduce the turbo lag?

Change gears so new higher gear still meshes above 1,900 rpm

AFAIK there are none or the manufacturer would have implemented.

It is after all the forced induction "Holy Grail". The engineereing solutions are smaller low inertia (low pressure) turbos, variable vane geometry turbos and twin-turbo installations mating a small and large turbo to the same engine, or a TSI where a supercharger beefs up response at low (pre-boost) rpm.