Is MATE still actively developed and maintained? I was under the impression it's even more on life support than Cinnamon…

Out of curiosity, which are the relevant features that were removed from GTK3? It should be possible to revive them in a separate library if they really are needed.

The ability to toggle gsettings for location-mode from path-bar (those button folder) defaults to filename-entry (the location bar you type in) is what really bothers me. It means I can't paste filepaths into a just opened File dialog (it errors out unless you first type ctrl-l, ., `, or /).

Additionally, the old type-ahead complete was removed from filename-entry. Arch at least has a patch set to put this back, but the location-mode thing is resistant to fixing. I changed the default initialization with a simple patch to gtkfilechooserwidget.c but it only works for the first time I File->Open in a gtk3 application. The second reverts back to pathbar.

Being able to copy / paste file paths is a feature that should probably exist, I'd imagine that would be accepted as a feature request.

It won't happen in GTK3, that's feature frozen. Maybe someone could implement it in GTK4?

I talked to mclasen on GIMPnet IRC #gtk a month or two ago and he did fix this in Gtk4. You can paste without typing anything beforehand in Gtk4 file chooser.

I don't think they will add settings back for that, but someone should be able to create an external file chooser that behaves differently.