Search accumulator on this forum. I have one on a mains cylinder and find it works for me.
Sorry I never read your post properly, You need to know your pressure first, an accumulator will give you plenty of flow but if the pressure is to low it won’t help.
It all very well saying how an accumulator can increase the flow rate and that you are happy with yours.
However, its unfair to say that without mentioning the limitation on how LONG the flow rate is increased!
Typically an accumulator will give out about 30-60% of its volume ( depending on mains pressure ).
So an 100 li accumulator would give about 50 litres of enhancement to the flow rate. If the mains only gives 5 li/min the accumulator could increase that to 10 li/min for a reasonable shower.
BUT it will only do that for 10 minutes ( and will need another 10 minutes to recover in that example ).
Tony