ok… ok… yes. my triangulates. well. do your way
actually… why the uv mesh should not to be triangulated? the edge visibility of source mesh based on:
#1 creation algorithm
#2 flatness of surrounded faces
in general case the uv might not match any of these conditions. so the not-triangulating the mesh is an subjective action as well as the triangulating.
Well, your way looks in fact pretty similar to some approach I posted here a while back, in which I removed the vertex position for optimization purposes.
So, as you can see, I had already evaluated that possibility but decided to not keep using it for the very same reasons I mentioned earlier, triangulation and shifted uvw.
It doesnt mean it cant be used, it is just that for this script I consider that the uvw topology is something that needs to be preserved. At least that is what I would expect from a script like this.
Also in the test I forgot to remove the delete and gc() lines from my function, which would make it run around 10-20% faster.
Overall, we are comparing the performance of two functions that leads to different results.