Why does Kaspa's block filtering matter most for inter-cluster communication?

Kaspa's block relay filtering is especially important between clusters because those links have less bandwidth and higher latency than connections within a single cluster. Kaspa's network is organized into clusters of nodes; connections that cross cluster boundaries are the most constrained paths on the network — they carry traffic more slowly and can handle less of it. By dropping blocks whose blue work falls below the virtual merge depth threshold before they cross these links, Kaspa avoids wasting the scarcer bandwidth on blocks that don't meet the quality bar. For a beginner, this means Kaspa is designed to stay efficient even on its most congested network paths, so the blockDAG can keep processing at high speed without inter-cluster links becoming a bottleneck.