Are there any limitations on tags or products?

For products, each variant has a limit of 13 options. So if a product comes in more than 13 colors, for example, the app will only display the first 13 as choices for your commenter to choose:

One more limitation in the product variant options is the name of the option. The option should be a single word. And Facebook has a limit of 20 characters for the buttons. So long option names can get cut off like this: