UniFi gateways (UDM Pro/SE/Pro Max/Beast/EFG) ship with notoriously underpowered CPUs and has no hardware acceleration for PPPoE. Paired with a PPPoE-based ISP connection, the performance is dismal. So why not hand the PPPoE dialing off to a dedicated device and let the UniFi gateway focus on routing, IDS/IPS, and NAT while breaking past 5500 Mbps of throughput?