Confirm there are not already settings or features that do what the shop is asking for- Confirmed. CommentSold does not currently offer a native product builder feature, custom file/image uploads at checkout, or shared inventory pooling across multiple separate product listings.

What does the shop want the product to do- The shop wants a customer-facing product builder that allows buyers to customize their purchase on their end, specifically by selecting a design image first and then choosing their preferred t-shirt color and size during checkout, all linked to a single blank garment inventory pool.

Why/how would it improve sales or efficiency- It would increase sales by offering customers a personalized shopping experience (choosing their preferred shirt color for any design) while driving operational efficiency. It prevents overselling by keeping inventory counts accurate in real time and eliminates the risk of promising unavailable stock to customers.