How should commercial food warmer capacity and structure be chosen?

Please verify the following points and require itemized written supplier responses:（commercial food warmer rice-warmer-selection） Choose capacity, opening, lid, handles, drain and mobility according to rice, soup, porridge, drinks or braised food. Prefer food-grade stainless steel inner containers, smooth rims, good seals and stable bases. Define capacity, accuracy, materials and operating environment before requesting quotes on a uniform basis. Request specification sheets, test reports, certificates, maintenance manuals and spare-part lists. During acceptance, verify appearance, dimensions, functions, safety protection and packaging, and keep test records. Do not compare unit price alone; include customization, freight, spare parts, after-sales support and downtime risk. Keep written records of inquiries, confirmations, FAT, acceptance and warranty commitments.