Something I did not see in the article are router specific tuning such as

    net.ipv4.ip_early_demux = 0
    net.ipv4.tcp_early_demux = 0
    net.ipv4.udp_early_demux = 0

in /etc/sysctl.d/10_router.conf to slightly reduce overhead when being used primarily as a router. There are many other router related knobs but those I would always set especially if trying to reduce overhead for VoIP/Gaming setups. There are many other knobs I tune such as gro_flush_timeout and napi_defer_hard_irqs, sch_cake tuning, lowat and output limits and hundreds more but those rabbit holes would require a large write-up. My overall goal is to give family members latency, jitter and throughput numbers that improve their quality of life and gaming scores of course.

Such things do not preclude additional tuning on the client and server sides as well but those are even bigger topics.