Leave one region out of the graph
Reference-bias map: use the *Suillus luteus* geography study as a source dataset, then rebuild the graph while withholding haplotypes from one region at a time. Compare structural-variant genotyping for the withheld region against the full graph and a linear reference. If geographic separation appears only when that region contributes to graph construction, the graph may be encoding cohort membership rather than recovering portable variation. Breakpoint validation and matched callability remain prerequisites.
