If you want to know whether your product is infringing, you can find a professional organization to help you search the existing patented technology.
In addition, if the high-heeled shoes produced by this manufacturer are patented (generally there are many appearance patents), then the manufacturer can directly sue those manufacturers who produce the same shoes. Only in practice, so those manufacturers are generally cottage factories and small workshops, and even if they are investigated, they have no money to compensate. Therefore, the so-called "seemingly divorced from god" is infringement, so just don't sue them. Anyway, if you have a patent right, you have the initiative. As long as you have proof, you can hit whoever you want.
If your manufacturer doesn't want the possibility of product infringement, then you should stick to the route of independent research and development, or pay more attention to the dynamics of peers, develop new performances or functions on their basis, apply for patents before putting them on the market, and avoid product infringement as much as possible.