It is pretty much all here.
You need to read the thread from the start.
Air goes into one side of the cylinder only, at some fixed pressure.
If the volume of the tank is large in comparison to the volume of the cylinder, then once charged to a fixed pressure to balance it, nothing else is needed.
The smaller the tank, the greater the pressure change from one end of travel to the other. Just have the tank volume a lot larger than the cylinder swept volume.
If the air temperature is much lower than when charged, the pressure will become lower. eg. hot summer, to freezing winter.
If you want it to operate over a wide range of temperatures, with no manual adjustments, then a regulator would solve this.
Alternatively, just use a counterweight, and no air complications are needed. Just a bucket of concrete.