I have a question that I haven't seen address in the article. Does the code always assume the "sphere" is Earth or can you provide geometric information for other geometries?
Or is it just assuming that the earth is a perfect sphere?
If you're curious about the topic, you can start here: https://en.wikipedia.org/wiki/World_Geodetic_System.
Since anyway the bounding boxes we calculate and the resulting areas we scan are larger than needed, so all the actual precision is in the filtering function that removes points outside the radius.
TLDR: It will be trivial to fix that later in a backward compatible way. Btw adding an item in my TODO in order to check if I can do it right now without compromising performances.