I'm not an expert so take this with a grain (or more) of a salt, but I'm pretty sure even amongst gen dials there can be some variation such as where the "m" is placed.
Nevertheless, if everything else is good, I would never in a 1000 years reject a watch for something like that. I'd pay more attention to the details that are prominent such as bezel insert, cyclops alignment, etc.
Plus, I think there's a lot to say about doing good business as a customer. TDs are doing something technically illegal and going out of their way to provide a quality product, and as customers I think we should not bust their chops over minute details. The relationship you form by being a reasonable customer will pay off in the long run.