The Crease Pattern for this model can be found in Shuzo Fujimoto’s books:
How to fold
If you know how to fold the standard square twist tessellation, you should be able to find out how to make the iso-area version by trial and error. Start by making a single square twist on one side of the model. For this design, I start from just the grid and don’t precrease the diagonally rotated small squares. In next step, turn over to the other side and make a square twist on the other side using one of the pleats that exit the back side of the molecule you made previously. The twists’ central squares on one side coincide with the X-shaped slits on the other. The only difficult part is finding out which part of which pleat to use once you have more than a few molecules already folded.