Some Linux distributions, language ecosystems, or research-data archives publish region-specific mirrors that block requests from foreign autonomous systems. Build pipelines that pull from those mirrors fail with 403s or timeouts when the build runner sits outside the allowed AS.
QPOL gives you targeted regional egress. Pick a node in the country whose mirror you need, route just the mirror hostnames through it, leave the rest of the pipeline direct. CI runners stay in their original cloud region for everything else; only the constrained pulls cross the tunnel.
This is also the pattern for accessing region-locked datasets in research environments. The dataset host blocks foreign IPs to comply with licensing terms; the researcher needs access for legitimate use; QPOL provides a node in the right country. The tunnel is narrow — only the dataset endpoint — so the institution's normal traffic isn't affected.
A reliability note: regional mirrors are themselves often less stable than the global CDN-fronted public mirrors. Combine the tunnel with a local cache and conditional fallback (try mirror, on 5xx fall back to global). The tunnel solves access; the cache and fallback solve reliability.