It depends on whether you are doing high pressure clamping or moderate.
My definition of high pressure clamping is clicking down until you have no in or out flow of blood…then you can unclick enough to kagal in more blood and pressure, and click it down again to hold it in. You can inflate to pretty high pressures this way.
The moderate way is that you click it down enough where is greatly SLOWS outflow, but you can still kagal in blood without loosening the clamp. This will allow you to have greater than normal pressure, but minimize darkening of the skin due to low oxygen.
So, to your question…multiple clamps in high pressure clamping will increase the pressure and hold it at the increased pressure…like squeezing your dick while clamped. You can put in anywhere on your penis and it will have the same effect.
Multiple clamps when doing moderate pressure clamping, when put side by side of the original clamp will make it even harder for the blood to leave, resulting in slighter higher internal pressure, while still allowing some circulation.
I personally like moderate pressure clamping with 3 clamps in a row at the base…it allows a fairly high internal pressure while still allowing me to kagal in more pressure without having to unclamp, and allows greater oxygenation of the tissue.
I should add that multiple clamps at high pressure is dangerous because it increases the pressure significantly and there is no safety bleed off of pressure.
When you multiple clamp at moderate pressures, the increased pressure will slowly bleed off, unless you are edging or watching some of your favorite porn, which will increase the inflow resulting in a higher sustained pressure. As soon as you stop the pressure will decrease. Because of this, multiple clamping with moderate pressure, or partial outflow…is not as dangerous as when you completely cut off outflow.