No it won't. It goes to the same regulator either manual or auto.It will draaw from tank selected on manual. On an auto it will draw from the higher pressure one first and continue on down to empty that tank.
There a lot of things I haven't sen and may a manual that will have setting in the middle and draw off both tanks. Not the best idea as you would want to full and hauling half full tanks and having them both filled would coast more, I think Run one down switch or auto switch and fill the other one. Then again maybe i ate too many beans.