These pumps can run very hot - my first pump wore out (severe scoring on the wobble plate) on the OEM oil. I installed a new pump and added my own synthetic blend (PAO/POE) and it has run noticeably cooler for the last five years.
Be careful as most straight SAE 30 non-detergent oils are SA or SB and may not take the heat. Personally I would use a synthetic SAE 30 SL or SM if you can find one, and if not I would use a synthetic 10W-30 SL/SM. I really don't know why they say to use a non-detergent oil, but I would ignore that in favor of a robust oil that takes the heat and has good wear protection.
Might want to write the pump manufacturer to ask the basis for their non-detergent recommendation. Perhaps they are concerned with possible water emulsion in a detergent oil, but I am not seeing any water in my pump oil.
Tom NJ