But why bother to complicate a system that works very well with a very little modification? Replace the pressurized cap of the small tank with a “simple” cap and the system works perfectly and degasses automatically.
A long time ago in France there was a humorous television series called "the Shadocks" it told the adventures of imaginary characters whose motto was "why make it simple when you can make it complicated?".
Without wanting to offend anyone, it seems to me that some of you would have made very good Shadocks. 