If you find a bug, please tell us so we can triage it. All bugs are managed in this GitHub repo. When you click through, our template makes it easy to record all of the details. Before you report a bug, please check our list of open bugs in case someone else has already reported it.
You can request new features in this GitHub repo. We also publish a list of open feature requests in GitHub. Check to see if someone has already requested the feature you want, and give it a thumbs up.