[itsme]

Here's a discussion about the diminished and half-diminished symbols:
https://www.logicprohelp.com/forums/topi...im-symbol/

User "I got the Sheets" seems to be looking for
ø = Latin Small Letter O With Stroke = U+00F8
Ø = Latin Capital Letter O With Stroke = U+00D8
For diminished chords I usually take the ° character = Degree Sign = U+00B0

Better and faster methods might exist to input these characters, but for checking if a font contains a certain unicode character the Windows character map (Zeichentabelle) is a pragmatic solution.
All the mentioned symbols are available in Roboto:
           

@Mike: would you mind mentioning also the fonts that you include into MobileSheets to be used for the other font options?