This was an issue for me and this thread was the only relevant thing I found so I figured I’d post here because it still comes up on Google.
I managed to solve the issue. SVG is only meant for 2D so it uses draw order for depth. You can fix z-fighting issues by moving layers closer to the camera so that they render on top of layers underneath them.
I wrote a script to automate this. It assumes that lowering the y axis value movies an object closer to the camera and that my SVG image is a collection named siamese.svg with all of the layers as paths nested in the collection that are ordered in draw order.
import bpy
MIN_TRANSLATE_Y = -0.0000001
counter = 0
svg = bpy.data.collections["siamese.svg"]
for path in svg.objects:
path.location.y += counter
counter += MIN_TRANSLATE_Y
The value -0.0000001 was picked through trial and error. It might need to be bigger if it doesn’t fix all the z-fighting. Hope this helps someone out 