How should drainage rate be evaluated when buying a lifting noodle cooker?

Don't trust the catalogue figure alone. Match drainage rate to your pot volume, strainer design and drain pipe diameter first: a big pot on a narrow pipe will never clear quickly. For acceptance, fill the lifting basket with water plus real noodle scraps and broken strands, then time the empty-out and watch for pooling or a clogged basket. Clean water draining fast does not mean starchy wash water will. Insist the supplier demonstrate the same batch on site, and if it fails, demand a larger drain valve or revised strainer before releasing final payment.