Reticulum has no bandwidth management. If your node or the whole local area is flooded with traffic from the rest of the network there is nothing you can do.
"Reticulum does not include source addresses on any packets" and with that you cannot throttle passing-through traffic based on source. Any hope of scaling is gone.
I believe the recommendation would be to use https://reticulum.network/manual/using.html#using-blackhole-... in such scenarios.