Vector is highly sensitive to how you set the eos switches as there is so much in this game that the upper and lower playfields are both tight . The eos are the easy way to regulate how powerful each of the 4 flippers are
It is not so much the gap, it is more the point at which the switch triggers that determines the power
As peter said, it is all trial and error to set these. And you will need to tailor each one. If you let vector be too powerful it will smash your upper drop targets and also smash the entrance to the vectorscan ramp
My paragon and fathom are similar aged ballys that required no such tailoring. But if you get the eos on vector right, it transforms it into a great and very playable game