Flatpak is quite big
$ flatpak install org.kde.dolphin
Required runtime for org.kde.dolphin/x86_64/stable (runtime/org.kde.Platform/x86_64/5.15-22.08) found in remote flathub
Do you want to install it? [Y/n]: y
ID Branch Op Remote Download
1. org.kde.Platform.Locale 5.15-22.08 i flathub < 355.1 MB (partial)
2. org.kde.Platform 5.15-22.08 i flathub < 321.2 MB
3. org.kde.dolphin.Locale stable i flathub < 6.1 MB (partial)
4. org.kde.dolphin stable i flathub < 31.1 MB
plus I suspect that I may need to manually fix configuration to fit my current Dolphin (like file thumbnails generating, storage) one + some other fixes: Getting Dolphin Flatpak to function as if it were installed in Plasma
I also read that upgrading Dolphin or similar part of KDe can cause “pulling in” most of KDE stuff due to a tight integration.
I have also not found a way to safely try to upgrade Dolphin from:
4:20.12.2-1
to:
4:22.12.3-1
so I guess i will have to wait until i be ready to dist-upgrade whole system from oldstable to stable.