The CSV1A can be turned up as high as 150 PSI. You just have to turn up the pressure switch before you can turn up the CSV. The regular Square D switch can be turned up to about 55/75 max. This would allow you to turn up the CSV to 70 PSI without the pump turning off. With a heavy duty pressure switch you can go as high as you want. With a pump that builds 200 on the inlet side of the CSV, the higher you set the CSV and pressure switch, the less the second CSV is needed. With a CSV setting of 75 PSI using a 65/85 pressure switch, there is only 125 PSI differential across the CSV and only one is needed. It is setting at less than 75 PSI that causes the high differential that would make a second CSV1A advantageous.
When adjusting a pressure switch, never mess with the small adjustment screw.