Newbie Questions on Identifying Out-of-Stock Products in E-commerce

Still relatively new to Clay, so these might be newbie questions: 1️⃣ Identifying Out-of-Stock Products – Is there a way to pre-filter e-commerce businesses that have products listed as "out of stock" or "limited availability" on their website or marketplaces (Amazon, Walmart, etc.)? I know Claygent can do this well, but is there a way to get a list of these companies before running the agent? 2️⃣ Any recommendations for optimizing prompts to get the most accurate outputs when enriching this "product out of stock" data from an existing list? 3️⃣ What's the best way to set up a timing trigger to refresh this data weekly/daily for personalization? Would love any insights—appreciate the help!