What is the function of cross bracing of interplane strut?
The cross bracing is to prevent the upper wing collapsing onto the lower one, the Bloop is an ultralight without the fuselage that the wings are normally attached to.

The two wing struts are in parallel and together with the parallel wings form a shape which must be cross-linked.. The bracing is for defining and retaining the structure and shape of the wings relative to each other, not to compensate for wing twist.

In the OP picture I cannot see any evidence of wing twist, only a constant wing incidence. The bracing wires need to be inboard only where normally the fuselage provides shape definition: in a classic biplane, there is no cross wiring required at the outer struts.