Not a Zoom employee here but my observation has been that the Meeting API seems to count the daily limit against the user account the calls are made on behalf of, not against the API account itself. i.e., doing create meeting POSTs to /users/emailZoomApiIsRegisteredWith@mycompany.com/meetings and /users/foo@mycompany.com/meetings count as 1 against foo and 1 against emailZoomApiIsRegisteredWith, not 2 against emailZoomApiIsRegisteredWith.
The above assumes that the OAuth App etc., is registered under emailZoomApiIsRegisteredWith@mycompany.com, and that foo@mycompany.com is a valid user account in your overall Zoom account.
EDIT (hit enter too soon!):
So in short, you may be able to change your API calls for the ones that create or edit meetings to a specific email address in order to work around.
That all said, your daily limit resets at midnight UTC