Yesterday, I installed xubuntu and added the kxstudio repositories to that on a friend's laptop. Everything installed and it worked fine.
The laptop that I'm on now, is running kxstudio, the v2 iso that falktx released for testing some time ago. I installed it, and once I'd pinned firefox to the standard ubuntu release, pkcon updated everything with no errors.
It all works fine and looks good, a running 18.04, kde neon, kxstudio. I'm very pleased.
My friend is noob to linux so I first tried avl linux but I found that it was rather tediously prescriptive, and there didn't seem to be a firewall installed. So, I know xubuntu well and installed that, signing the nvidia driver for optimus, which was hassle.
Just add linux-lowlatency kernel, edit the /etc/security/limits.d/audio.conf file, add the user to audio group, set vm.swappiness down to 1 (no swapdrive), install cpufreqd, add noatime to fstab mount, and install the kxstudio meta packages, as well as add the menu, and adjust the theme.
It looks good and works well.
I used to be a user of ubuntu studio, to which I added the kxstudio packages, but the recent release with ubuntu-studio-controls is tediously anti free as in speech. It incorporates jackdbus, which I couldn't seem to download from repositories as a separate pkg, and so you use ubuntustudio, with jack, only if you use ubuntu studio controls. Being forced to use some set up or other is so against the linux core philosophy, that I won't go back to the project until they have kicked the twerp that has created this proprietary situation, and released ubu studio as it should be, with ultimate configurability and no dictation as to what we should and shouldn't install.
In the meantime, I can recommend xubuntu with kxstudio repositories. When you first try and add a package, apt might complain that you have held broken packages, but this can be overcome by running $sudo apt-get -f install.
I don't know how long the repositories will be valid for, if there is no development going on, but its good for now.
I am also working on, when I get time, a fedora install, with kxstudio packages, particularly plugins, installed. I have written a piece of software using pyqt for the gui, with python backend, to download deb packages from launchpad, and then convert them using alien and install them, keeping track of the installed files. Its at
https://github.com/millerthegorilla/launchpad_rpm.
Hopefully I will be able to get kxstudio packages like cadence, which I am a great fan of, as well as the tools and plugins to install and work on fedora. It seems to work so far, but I haven't tested it massively, yet.
best of luck