“Too many errors. Temporarily blocked.” with HTTP response code 429 means that something about your account or project specifically was bringing down the entire service for everyone.
We have removed all such blocks as of today, May 22, 2023, but we will add them again if needed to safeguard the availability of KoboToolbox for other users.
Has something changed recently with your project? Are you collecting more data or running an automated task to fetch exports?