The CIAT/CropTrust proposal for the calculation of “Comprehensiveness of conservation of socioeconomically as well as culturally valuable species” is up on the Biodiversity Indicators Partnership website.
Here’s a recent blog post on the indicator, which is relevant for Aichi Target 13 and SDG 2, Target 2.5.
And here’s the underlying paper which described the method in detail: Comprehensiveness of conservation of useful wild plants: An operational indicator for biodiversity and sustainable development targets.
Finally, here’s the website where you can explore the data.