Only the dreamer venoms all his days,
Bearing more woe than all his sins deserve.
My only thought setting up diagonally would be the amount of surface area an 8x10 has with only four tie-down spots (two stakes). If the wind picks up it may not hold or it could flap a lot.
It can be staked down as a hex tarp with the "corners" either draping perpendicular to the ground or even staked down as well.
It works. I use the same tarp in multiple configurations. On windy days I use more than two stakes. I really like the sil 2 and the flexibility it offers.
+1 on the simplicity and value of the stock HH tarp though. I am considering going back to it for some outings too.