Setting containers/sinks to take the remaining production per minute, instead of stealing it from the other buildings

I want to plan out in a way that some of the surplus goes into a container or sink.

Currently containers are the only building you can’t set the items per minute of either input or output, and if you connect it alongside other things, it will “steal” the items per minute used by other buildings, doing an equal split.

I want to know how much surplus I could gather, but the options are either this or not connecting a container and just seeing that some nodes in the production are underperforming, and they could do something.