You mean when demand > supply? Because otherwise output = demand, H2 use adjusts to demand.
Or do you mean "demand if all machines would work at the same time"?
Always display as current demand / reactor supply. The ideal situation would be all machines are 100% utilized, including the reactors, so the demand should be sometimes higher than supply, draining the battery; sometimes lower and recharge the battery. Display as current demand / reactor supply would give good information in both situations.
I would say this is the current state, no? Not sure I understand in which scenario you would want something else than is the case right now.
- demand < supply: part of the bar is filled showing non-used capacity
- demand = supply: bar 100% filled (this happens also when charging or discharging the battery)
- demand > supply: bar is 100% filled, total of the progress bar is demand now instead of supply and overdemand is shown in red to show how much you need to upgrade the reactor.
Honestly just adding a % of demand satisfaction would help a lot, because often you don't know if you have 101% of demande satisfaction or 150%.
What you describe is only true when your battery if full, when it's not you jsut see your battery filling and have to place mouse on it and do the math to see how much oversatified the network is.