Most critical issues found with Bitbucket pullrequest builder plugin is no control in triggering builds by open pull requests. When the plugin is initially installed & configured, all open pull requests will be triggered, which might crash the system when there are many open PRs. Besides, whenever a user creates a PR or commits a change, the build will be triggered, causing massive unnecessary build processes and failures. Users like to control the triggering of builds when it's ready.
Suggestion: add a checkbox like below
|Only build if asked with the build phrase|