Please bear with me on this one. You are probably aware that the status of Foreign Language Braille rules has been sometimes a bit unclear and that this is all to be resolved soon because new rules are (FINALLY!) under BANA review.
I have a pencil notation in my rulebook from 2005 that indicates per the Foreign Language BANA committee chair that the slash is to be brailled spaced the same as print for all languages the way it is in English. So just carry on and braille the slash as it is in your print and ignore those two provisions about spacing the slash in those various languages. Space the slash as in print in all languages.