How to find the distance between two point efficiently. Have used Linebuilder with a larger dataset and it takes ages, workspace with test data is attached.

You can also try using a NeighborFinder with a Group By on a common attribute. Just make sure that the maximum distance is sufficient to account for the longest possible line. You'll get the distance as an attribute "_distance".

Thanks for the complete set of test data. If you upload a workspace template (fmwt) the data is already added, you don't need to upload is separately.

If I test this the GeographicLengthCalculator is slowing down the process, not the LineBuilder. This is because every line is being reprojected from LL84 to _AZMED_, measured and then restored to the original geometry.

I'm not sure if I know a faster way to solve this.