If the Reasons are just a blank to be filled in, place the opening Nemeth Code indicator in cell 1 on the line before "1S" and braille the entire proof in Nemeth, using the "long dash" of the Nemeth Code (36, 36, 36, 36) in the numbered "R" entries.
If the "Reasons" column contains words as well as blanks to be filled in, you will need to switch codes as needed, following the list format described in Sec.194. It is not necessary for the "#S" and "#R" identifiers to be in the same code.
The alternating "S" "R" format outlined in Sec.194 is only a suggestion. If another format makes more sense in your particular proof, by all means try it. I can provide ideas if you attach an image of the print page.