@anselmschueler testing...

1.234/-12 (normal slash)
1.234⁄-12 (Unicode)

٠٫٢٥/12 (normal slash)
٠٫٢٥⁄12 (Unicode)

二/三 (normal slash)
二⁄三 (Unicode)

Ⅲ/Ⅳ (normal slash)
Ⅲ⁄Ⅳ (Unicode)

No decimals, no negative numbers, no Roman numerals or other scripts... not quite what I had hoped for 😅, at least in Tusky's preview rendering, let me know if someone sees it working correctly in any of these!