To deal with overflowing byproducts what I did was stop supply of a main resource i.e. sand gained by crushing, by using a belt circuit connected to the network to read total sand supply. It will only fill up the supply depot if there is less than 5k sand available to pick up.
This ensures the sand byproducts from Imersite crushing sites don't overflow, ever. Because drones will be coming to get sand from there instead as it's the only one providing it.
The same can be done with fluids especially trying to get rid of excess chlorine overflow. Just use a tank and a pump before a fluid depot, connect tank to network to get total reading. Wire pumps to control flow.
Edit: my gripe with fluid depots is they won't accept a wire connection, so it's a bit of a hassle making storage tanks to to send supply info to the network and using circuit controlled pumps to control both directions.
