If Stash could detect/remember the base branch from which a feature branch is created, it could automatically pre-select it as the destination during pull request creation.
— Original suggestion —
This would be useful for when you need to merge pull requests for release branches e.g., fix/1.x/bugfix into release/1.x. When a pull request is created, the correct release branch could be selected automatically. This will be a pleasant experience and reduce errors caused by having the default branch selected by default for the destination.