Your thinking is logical and clearly explained. However, it is not quite in line with the Guidance for Transcription Using the Nemeth Code within UEB Contexts. This is because #5 under Additional Guidelines in the Guidance applies to standard units of measure, namely those from the US customary units system, the metric system, and the International System of Units.
So, the braille you provided in your Example 2 is correct.
Thank you for your question and your time.