PiP Vase Mode Large Phone Charging Holder

I'm quite happy with this design. I'm leveraging the fast print speed of vase mode / spiralized outer contour along with the stiffness of 2 interacting surfaces to make a light weight yet strong and fast printed object of good size.

There are two tricks in this design:
(1) There's a 0.1mm gap at the bottom of the phone holder. This gap is large enough for the slicer to see it as a gap but small enough that the two parts still fuse together. Thus, the 0.1mm gap allows for an 'inner' layer to the spiralized outer contour. [BONUS] I've made this gap 'jump' around to improve fusing.
(2) The gap between the 'inner' and outer layers narrows down to 0.5mm at the valley of the ripples allowing the outer layer to fuse with the 'inner' one.

The radial corrugation created results in a very stiff structure without the use of much material!