Streaming audio files from SMB (or AFP, or NFS) share to DLNA receiver without resampling
If anyone else is seeking for a similar solution, I think doubleTwist player uses a combination of android's media scanner and it's own directory scanner to import music. So the method with mounting the SMB share kind of works here. But it doesn't import duplicate files (support told me they are thinking of doing something about that, also a workaround may be possible by editing any of the major metadata tags like Track Title, Artist, Album Artist, or Album Name - will have to try that, but that involves editing of the files which not everyone might like), so if you have same songs (maybe slightly different versions) on several folders, you can't import them all without altering the files, yet.

Another option is n7player with Toastercast plugin. It works kind of good, but it takes a long time to scan the music folders (about 4 hours for ~14000 songs). And I'm not sure yet if you have to rescan the whole library when you add new music, but I fear you do.. Also, for me this setup would stop playing after one song if the screen is off. I don't know if it's related to android's battery saving or the mounted folder.

And one more promising app would be Emby Server for Android, it can access the SMB share on its own, so I guess it would be a cleaner solution. It is still in beta stage, so for now it doesn't find my DLNA renderer, but I'm keeping my fingers crossed for that to be solved.

Update: I think, adding the .nomedia file to the mounted directory helps the android's media scanner not to cause random crashes. But this approach only works if you use a media app, that scans directories on its own, to add files to the library. And it would be a good idea to store the media files at least one folder level lower, than the .nomedia file, because android's media scanner will not scan the subdirectories of the folder which contains the .nomedia file, but other media apps may not scan this folder's contents, but might scan the subfolders.