Taxon Framework Relationship error

As a start to this project I’d like to get a handle on what TFRs are currently defined for Cactaceae. Is there any way I can download all active TFRs for decedents of Cactaceae as a CSV file?
I can query them using the TFR index page with “Cactaceae” as the external taxon as here:


but the equivalent query with “Cactaceae” moved to internal taxon fails, I get all TFRs under Trachaeophyta!

@pisum Can this be done through an API call?