Hi Robert,
I would not do it as you’ve done in the example. Single-line format should be single-line, not two lines like that. I would just braille it as you would any other piece. Intervals are read upward in the bass clef, so when the octave intervals begin, you’d braille the 2nd octave G with a doubled octave interval after it. The directions tell the reader what they need to know. No reason to add parentheses that aren’t there in print or make it more complicated than it needs to be!