sadly in lemmy's own default web UI having space's between the subscript text will just render normal text with tildes on both sides. That's why I put tildes around every word. I recall there was a discussion half a year ago how every app / frontend has a bit different levels of support for markdown.
ahh thought that was already part of standard markdown :( hope they extend the markdown definition soon. It's getting crazy how many "flavours" there are!