Which issue is clarified by distinguishing pillar and attribute?

Performance and Substitution: Complete and Deficient Adāʾ and Qaḍāʾ

• Treating every defect as an issue of timing alone
• Assuming a single remedy corrects both pillar and attribute omissions
• Whether a defect affects the act itself or its required quality
• Classifying every act with a missing attribute as complete adāʾ