You can produce products. If the patent belongs to someone else, you can't write whether the patent number is valid (unless others agree, of course). If it is your own patent, you can write the patent number on the product as long as the patent is still valid. I don't know what you mean by non-patentability after retrieval: 1. If you are judged to be non-patentable by comparing the documents retrieved by China National Intellectual Property Administration in the application review stage, and the patent is rejected or deemed to be withdrawn, it means that you have never obtained the patent right at all, and of course you can't write the serial number as the patent number on the product; 2. If the evaluation report of the authorized utility model you requested says that it is not patentable, it's really hard to say. The evaluation report does not invalidate the utility model, and the patent right still exists. It should be possible to continue to mark the patent number, but this is somewhat unreasonable. The patentee knows that his patent is not patentable and still marks the patented product, so he is not sure what will happen in the future.
As you said, the retrieval report is not the basis for judging the validity of a patent, but the significance of the patent retrieval report lies in providing the existing technical data closest to the patented technology, thus serving as a reference for judging the validity of a patent. Then I think, since the patent right has not been invalidated, you still have the right to indicate the patent number. The probability of subsequent problems is not particularly large, and the consequences will not be very serious. Personally, I think we can continue to mark.