The Tarptent-for-2 is just a larger version of the original Tarptent. Because it contains 20% more fabric than the Tarptent, gravity exerts a slightly more pull on the fabric and the roof may experience more sag (fabric depending, see All in the Fabric ). This is particularly true in the rear of the tent because the walls are less steep than in the front.
If you experience unacceptable sag, there is a way to eliminate nearly all of it. The idea is to exert additional tension in 2 directions in order to lift and tighten the material. Rather than use additional stakes, simply add pullout loops and tie them off to the existing stake.
Here's how to do it:
Cut 3.5 inch webbing strips and sew to the underside at the positions shown. Tie a cord (or webbing strip) between the side pullouts. Now tie a cord loop around the side-loops cord and tie the other end to the corner pullout. Repeat for the low rear corner if necessary.