My paper on matrix-based methods for regionalized life cycle assessment is available on EarthArxiv. My co-author and I tried twice to get this through peer review at a high-quality journal over the years, without success. However, I think this was the hardest and best bit of scientific method development that I have done, and probably will ever do. If you are interested in the incorporation of spatial information in life cycle assessment, you might want to check it out. You can cite it as:
Mutel, Christoper; Hellweg, Stefanie (2023): Matrix-based Methods for Regionalized Life Cycle Assessment. EarthArxiv. Preprint. https://doi.org/10.31223/X5537N.
I should note that method 3 was an idea that never really panned out, as LCIA method developers haven't supplied the data to give the spatial weights; if I were to rewrite the paper I would leave it out.