Why is text replacement not working everywhere?

I use a lot of emojis in names and bodies of notes. Each emoji I use has a special meaning to me and helps me to focus and classify.

All the emojis I use are set up in System Preferences > Keyboard > Text with 6-character strings.

Somehow I cannot fully use the text replacement feature of macOS in DT3.

It is not working in the search feature nor in the body of a rich text note.

Can this be fixed please?

Is it enabled in Preferences > Editing?

I enabled it and had to restart DT3 to make it work in the body of a note.

But searching for an emoji does not work.

Emojis aren’t indexed, only alphanumeric characters are currently indexed & searchable.

It’s also generally not a good idea to use emoji in filenames.

Emojis are Unicode characters, could they be indexed and searched please?

Searching for emojis works very well in other apps such as Agenda.

Why?

Behavior that is more broadly supported is always preferable, especially when legacy systems (e.g., applications and servers) are involved.