I should add, in case it’s not self evident that badges are images and emoji that you type are font characters. In order to use emoji as badges you will need to find a set of images of the emoji characters. You can’t just type a letter (be is ‘a’ or some Unicode number) and have that font character appear as a badge.
So unless you have, or can get a set of 32x32 pixel PNGs of emojis, I’d suggest abandoning this approach.
Conversely, as emoji are fonts you can use them in note titles and text. I’d caution against using them in titles if you’re going to need to search against them (I don’t know how those sort of characters get handled in things like find)proved wrong - see further down thread. They might work though used in Subtitles or Captions though noting these two features are essentially used in Map view only (which appears your preferred view type).
Edit: corrected false assumptions re emoji as unicode characters in find, queries, actions.