That was a good read. One thing not explicitly addressed is that this failure is not just about duplicate waypoint names, but about converting between sparse and dense data. In this case the problem was in converting dense (higher resolution) to sparse (lower resolution).

Knowing nothing about the systems involved and not really following the proposed solution, I can only ask a question: Is the dense data fully available and understood by the engineers doing the conversion?

If so, the conversion software can start by identifying the entry and exit points in the source (dense) data. (Start at beginning and look for the first “UK” entry to get the entry point. Start at the end and look for the first “UK” entry to get the exit point.) If there is no match in the destination (sparse) data, search outward for matches. When matches are found, these represent the actual entry/exit points within the limitations of the sparse data. (Perhaps this is exactly what the proposed solution is doing!)

If, as I understand, there are no duplicate identifiers within a region’s span of control, that should be the heart of a general solution that then “digs deeper” to check for fragmentation (flight plans that enter and exit regional control multiple times).

Or maybe I understood less than I thought and am completely out to lunch. :)