Autohotkey 2 using InputLevel for a hotkey in a hotstring not working

Question

Autohotkey seems clear that you can use a hotkey in a hotstring by using#InputLevel, but none of the four hotstrings below work for me. If, instead of using \ in the hotstring, I use some un-mapped key then the hotstrings work.

#InputLevel 1
#::\

#InputLevel 0
::1\2::½
::1`\3::⅓
::1#4::¼
::1`#5::¼

How do I get the hotstrings to work with the backslash?