Check out NanoPI R6S with OpenWRT - #380 by choppyc in particular as well as the handful of posts preceding it (enable irqbalance and disable packet steering). I modified the core allocation slightly to leverage the higher frequency cores. Not sure if it really makes a difference.
friendlyarm,nanopi-r6s)
set_interface_core 2 "eth0"
set_interface_core 6 "eth1"
set_interface_core 8 "eth2"
find /sys/class/net/eth*/queues/[rt]x-[01]/[rx]ps_cpus -exec sh -c '[ -w {} ] && echo ff > {} 2>/dev/null' \;
;;