How to reduce bitbucket API usage?

[HolisticDeveloper]

We have a little over 50 jobs that are configured to do PR builds with this plugin. I recently found that they weren't working reliably, and the logs pointed to exceeding the Bitbucket API rate limit (which is 1000/hour according to the docs. Even after reducing the polling frequency to every 15 minutes we still hit the error occasionally.

Are there any suggestions to reduce API bitbucket usage (other than changing the cron settings)? Are there any specific factors that result in more API calls (e.g., number of outstanding PRs)?