SFTP: Configure and use custom filesystem adapter
By default TElSimpleSFTPServer creates an instance of TElDiskFileSystemAdapter when the first filesystem-related command is received, and initializes its BasePath property with the value of SFTPBaseDir property.
Additionally each user, added to the Users database, can have its own value of BasePath property, and it will be used for this user's SFTP session.
If you want to create a custom filesystem adapter or just have your own instance of the adapter being used (eg. SolFS adapter), you need to put a reference to this adapter in TElSimpleSFTPServer.FileSystemAdapter property.