fish protocol in kate 15.x

[Hamlet]

Dear all,

I have faithfully updated my Gentoo ~amd64 box with whatever comes with it, that includes pieces of KDE Frameworks 5.
It happens that kate editor was updated to version 15, and I have some trouble with it.
The most important feature I can't make work is editing remote files with SSH (fish protocol).
The "Open" dialog window doesn't even allow me to type an address for the source directory, and its drop-down options are rigorously local.
Please save me from SSH + vi!
Another feature I badly miss is favourite locations and bookmarks.

I believe I am still basically using KDE4 (startx with XSESSION="KDE-4"). I don't know if these issues would be solved by using a "KDE5", I don't know if such a thing already exists, if it's provided in Gentoo, if it could co-exist with KDE4 installation, if moving to it is reversible and if moving to it will drop me in a hell of "not implemented yet" features (fish might be one).
I starve for information... thank you!

(edit)
I was missing some vocabulary, in particular the "Plasma5" word. I could find useful information about what I called "KDE5" (https://wiki.gentoo.org/wiki/KDE/Plasma_5_upgrade), but my question about FISH stands: can I use it with kate 15 and KDE4? can I use it with kate 15 and Plasma5?

[Ant P.]

You need kde-apps/kdebase-kioslaves for KDE 4 apps, kde-apps/kio-extras for KDE 5 apps.