ASTM E2500 and URS

Would someone be able to provide some guidance please on the application of ASTM E2500 (Standard Guide for Specification, Design, and Verification of Pharmaceutical and Biopharmaceutical Manufacturing Systems and Equipment), regarding specification of user requirements?

I am new to validation of manufacturing / process control systems as my background is validation of analytical and information systems, but I am applying the same principles and am very familiar with the GAMP guidelines.

My understanding is that all user requirements must be specified in the URS. However, ASTM E2500 seems to suggest that only critical quality attributes and GMP requirements need to be specified. If the URS omits non-GxP requirements, which may be important for operation, efficiency, safety etc., how can it be ensured that a system fit for intended use will be delivered? Additionally, shouldn’t all user requirements be specified before critical quality attributes can be identified (through risk analysis)?

Any thoughts or guidance on this would be much appreciated!