OK, so do we agree that looking for the "smallest difference" on the graph like you did has actually no practical use in analyzing the data?

Can you also please cite your source that it's a "data import code" problem as you claim above? I don't see it in the article and I understand the article differently, I consider the assumptions they used being correct ones for the given data sources.

Edit: I see your edit and I don't agree with your claim "it's just not the popular perception on either side of the debate" -- "it should warm the same everywhere" is only actively used by the "deniers" even if no scientist ever made such a claim:

https://www.climate.gov/news-features/climate-qa/does-global...

https://www.treehugger.com/natural-sciences/uks-met-office-r...

etc.