I had no idea kio-fuse was being worked on. This is awesome! gvfs (and its FUSE implementation) was my favorite feature of GNOME and was the reason I primarily used Nautilus on KDE on my work VM.
Yes, finally in 2020 Dolphin can open a file from an SMB shared folder without making a local copy, which basically made KDE unusable in any environment that involved editing files on a Windows share.
Took a while but it does work, bar a few minor issues. I have problems with certain applications not understanding Dolphin has already authenticated to a share. For example VLC will only open a file if the URI to the share contains the user name required to authenticate (smb://user@fileserver/Video).
