I'm really liking that texture. It looks awesome. Great work, there.
We've been doing similar routing on 4' x 8' PVC sheets, bonding two together back-to-back to form a double sided sign. These are typically text and numerous governmental logos for parks and projects. I'm using Enroute 3 and am looking forward to upgrading to version 4 for the textures.
The time to route PVC isn't so bad. We cut at 168 inches per minute, using a 0.250 bit. to give the job a uniform depth and bit width. Then, we go down into 0.125 and 0.0625 at much slower speeds for detail passes. If we upgrade to Enroute 4 and put a texture on the background, I'd be able to use a larger bit to cut the field (like a 3/8" or 1/2") at a significantly higher speed, since the texture would blend out the widths of strokes.