Second, I very much sympathize with your question about, “How should we format formal proofs (and other labeled statements) in UEB Math/Science transcriptions?”
In short, Braille Formats is our formatting guide for anything not covered in RUEB, GTM, or BANA’s “Provisional Guidance for Transcribing Mathematics in UEB.”
One covered issue that is related to formal proofs comes from the “Provisional Guidance for Transcribing Mathematics in UEB.” The first paragraph in #3 of that document says the following.
For technical materials, use margins 3-1; do not use blocked paragraphs. If the entire textbook is in blocked paragraphs, note the change to indented paragraphs in a TN.
So, in a UEB Math/Science transcription, we would probably format the print of “Example 26-73: Theorem with Auxiliary Captions” of The Nemeth Code as follows.
⠀⠀⠘⠂⠠⠮⠕⠗⠑⠍⠀⠘⠂⠼⠙⠲⠀⠠⠊⠋⠀⠞⠺⠕⠀⠇⠔⠑⠎⠀⠜⠑⠀⠉⠥⠞⠀⠃⠽
⠁⠀⠞⠗⠁⠝⠎⠧⠻⠎⠁⠇⠀⠯⠀⠁⠀⠏⠁⠊⠗⠀⠷⠀⠁⠇⠞⠻⠝⠁⠞⠑⠀⠔⠞⠻⠊⠕⠗
⠁⠝⠛⠇⠑⠎⠀⠜⠑⠀⠑⠟⠥⠁⠇⠂⠀⠮⠀⠞⠺⠕⠀⠇⠔⠑⠎⠀⠜⠑⠀⠏⠜⠁⠇⠇⠑⠇⠲
⠀⠀⠨⠂⠠⠛⠊⠧⠢⠒⠀⠠⠇⠔⠑⠎⠀⠰⠠⠠⠁⠃⠀⠯⠀⠰⠠⠠⠉⠙⠀⠉⠥⠞⠀⠃⠽
⠞⠗⠁⠝⠎⠧⠻⠎⠁⠇⠀⠠⠠⠗⠎⠀⠁⠞⠀⠏⠕⠔⠞⠎⠀⠰⠠⠑⠀⠯⠀⠰⠠⠋
⠗⠑⠎⠏⠑⠉⠞⠊⠧⠑⠇⠽⠆⠀⠸⠪⠭⠀⠐⠶⠀⠸⠪⠽⠲
⠀⠀⠨⠂⠠⠞⠕⠀⠨⠂⠠⠏⠗⠕⠧⠑⠒⠀⠰⠰⠰⠠⠠⠁⠃⠀⠼⠇⠀⠠⠠⠉⠙⠲⠰⠄