Development releases are snapshots of the ongoing Confluence development process. As such:

• While we try to keep these releases stable, they have not undergone the same degree of testing as a full release.
• Features in development releases may be incomplete, or may change or be removed before the next full release.

Because development releases represent work in progress, we cannot provide a supported upgrade path between DRs, or from any DR to the eventual final release. So it's possible that you won't be able to migrate any data you store in a Confluence DR to a future Confluence release.