As mentioned in yesterday's article [0], they can't be used because they haven't been mapped to a Unicode code point:
> (A note on most of these characters is that they don't actually map to any defined Unicode code point; they are unconnected glyphs. Font Book will show them but you can't really copy them anywhere. A tool like Ultra Character Map will let you at least grab a graphical representation and paste it somewhere, as I have done here.)
0: https://tenfourfox.blogspot.com/2025/08/mac-history-echoes-i...
You can open them in a tool such as FontForge and force an encoding. You might need to add some padding at the beginning so that you get the symbols on a usable range.