I know from past experience that I’ll run into issues without this addon; I often need to create cards with identical first fields.
Has the functionality of Ze Add Note Id somehow been incorporated into Anki with 23.10? Otherwise, I’ll be stuck with 2.1.66 …
Cheers 
If you want to create notes with identical fields, you can make these fields sticky, which is has been built into Anki for quite some time. If you need the add-on‘s specific functionality (https://ankiweb.net/shared/info/886709118), you need to install it again.
No, this is NOT what Ze Add Note Id is for … 
From the manual:
Anki checks the first field for uniqueness, so it will warn you if you enter two cards with a Front field of “apple” (for example).
Ze Add Note Id adds, you guessed it, the Note ID before the first field, so that all cards will always be unique …
Recent Anki versions do not prevent you from adding multiple cards with the same first field. The other use for Ze Add Note Id was to provide a unique identifier when exporting+importing csv files, but recent Anki versions can include an internal unique id for you automatically.