webdav mapping to storage access framework?

Hi,
is there an app outside, which maps a webdav cloud service into the storage access framework of Android?

My actual use case is KeepassDX, where I would like to use a kee-database on a webdav-drive. But other apps are also using the storage access framework (SAF) to load or save files.
At the moment I see only Google Drive within this framework.