Apply only before production. Production will not affect the approval of utility model patents. And there will be no legal issues affecting patent protection.
And in the current actual situation, products are basically produced directly after applying for a patent.
Like invention patents, the general review cycle is more than 2 years. Once a patent is published, everyone can know the patented technical solution. So if we had waited to get the certificate, someone else might have already produced the product and sold it. Although situations like this can be curbed through legal means, it will cost a lot of litigation costs.
To sum up, as long as the application is submitted, it can be produced immediately. There will be no negative impact at all on patent protection.