In a literary situation, when I have “2.a,” do I use the decimal point or the period? Section 4.3.8 covers this to some extent, but only for headings. I’m assuming I can transfer the same principles to non-heading text. The guideline addresses number-number and letter-number situations, but not number-letters.
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.