I have a cheap/quick/dirty deer and rabbit fence around our vegetable garden. The doors are simple PVC squares with deer netting that used to attach to the fence via hooks at the top. This design turned out to be very fiddly. The new design seems much easier to manage - simply drop the door section into its slot.
Is ABS problematic in sun? I wouldn’t think it was, since it’s been used for decades in the automotive world on exposed stuff (I have a 90’s motorcycle with a fair bit of exposed ABS and it’s surprisingly fine).
Maybe the auto world has additives for stability?
ABS generally requires additional additives for UV resistance, and plain ABS will degrade relatively quickly in full sun.
There’s a section in this study on the change in mechanical properties of ABS resins in simulated weather environments https://mirror.wide-net.org/pub/b/plastic/abs-yellowing-etc-CIB9222.pdf