That’s correct, moving between applications is not designed as a way to move between different instances of the same codebase, and therefore old data is deleted as it’s assumed to be not needed in the new app.
Note that we do want to bring the staged releases functionality to the dashboard. For now it can be used with the staged releases scripts, but also with our SDK, e.g. Balena Node.js SDK - Balena Documentation
The ability to deploy multiple releases from multiple git branches that would target different devices in the same application would be great.
Once you disable rolling releases from your app, you can push arbitrary branches (either with git push balena branch:master or using balena push as described here balena CLI Documentation - Balena Documentation ), and then use release tags, device tags and device pinning to achieve this arbitrary mapping between what releases are run by what devices. This still requires a fair amount of scripting, hopefully things will get easier as we start surfacing these features on the UI.