Whether or not UPS considers those ok for work is totally random and subject to change at any moment. For years people will wear something and nothing will be said. Then boom - one day they're not acceptable. Then a few days later, they're fine again. Drivers wear all kinds of shoes that aren't technically in compliance and they rarely say anything. Unless it's a keter week, that is, or if the DM is coming up for the day. Then it's code red, and uniforms, shoes, and shaves better be in order - this will be driven home at the PCM in the days preceding their visits. Repeatedly.