Pressure / Overflow Valves for fluid storage

To work along side the balancers' so you could control storage based on levels in the tanks,
I have set up the generators to run off Fuel Gas, then Heavy oil, then go to Coal automatically using the pipe/conveyor balancers, but it would help for the gas to build up volume in the tanks before being released to run the generators, instead of stop/ start cycling.

Currently it can be achieved by a balancer prior to storage input. A simple solution with existing mechanics. That does not justify investment in remodeling existing storages and introducing new mechanics. Because in the end, it will be equal to a storage with balancer.

An overflow valve to allow desired pipelines to eliminate their surplus. In order to avoid a complete shutdown of certain machines that produce multiple chemicals. Allowing a constant flow with better use.

I agree that integrating an overflow outlet on fluid storage (maybe just upgraded levels) would be ideal. I almost always build a pipe balancer before the storage, so having it integrated would save me ~4 squares per storage.
I could see it working in either of two ways, roughly in order of my preference:
1) Merge some balancer features into the fluid storage, so that I can specify which outlet pipe is the priority. If no priority is set, they both work as normal. If one outlet is prioritized, the secondary pipe only releases product once it hits the overflow level (which, ideally, I'd also be able to specify)
2) Add a dedicated outlet pipe to the fluid that only releases product once the unit is full
Cheers!