I would tend to agree with you. Pump filters can clog, and they will in time need manitenance. Since it is unknown to me the extent of the system and the redesign and permiting issues, it is hard to say for sure.
Where I live drip irrigations systems operate at 20-30 psi. The last place I lived had common areas that the drip systems were 2-300 yards long. They used pvc pipe but everything after the valve was low pressure.
I am convinced living in the desert that anyone who sprays water into the air is nuts. My new lawn has no sprinklers. I am currently using the hose to "flood/irrigate" the lawn. I believe if I stay here I will build a system similar to what I am doing now.
I know for sure that if the lay out is correct the 58 psi or even lower should be fine as long as it is zoned. A given spray head will not cover as much area on 50 psi as it would on 60 psi. So you may hate the fact that your going to need more heads, zones and a bigger control box.
Where in the world do you live that requires irrigation to be approved by the city fathers?