[ChrisH]

You can also use an extra cylinder as a storage tank. Many teams did this last year. However, there is a price:

First, it means one less actuator. A cyclinder used in this way must be mounted in such a way that the piston does nothing at all. Preferably you use the retract side of the cylinder as your reservoir. That way the piston wants to stay in. But if you have the space and need the volume you may have the piston fully extended.

Second the piston adds weight and potentially removes volume, though not very much.

Of course, if you do this you want to get the biggest cylinders on the list. Remember that you are not allowed to modify the cylinders in any way. So don't even think about cutting off the piston rod.