As you have implied, this is a literary EBAE question, so I would post this at the literary braille forum. I think that what you have cited here is the statement from Formats that shows how this basic braille EBAE formulation is applied in a specific format, namely, headings. Formats is going to address formatting, after all. My understanding is that ANY letter/number combination such as this, uses the period and the decimal is used only between numbers. I don't think it matters whether it is a heading or not. But you might inquire over at Literary Braille because that is the jurisdiction of this question.