I Dont Know If This Will Work On All Systems But I Run
Arch Linux
KDE Plasma Version: 5.21.5
KDE Frameworks Version: 5.28.0
QT Version:5.15.2
Kernel Version: 5.12.5-arch1-1
OS Type: 64-bit
Graphics Platform: X11

download qmods installer, use winetricks to install dot net 40 then in winetricks still go to to winecfg make sure to go to library and bypass version and winhttp, Run Qmods installer point it at the subnautica below zero folder, then run "protontrics --gui" in the terminal and select subnautica below zero then clicked on the exe in the folder so it could bring up the games winetricks and did the library bypass with version and winhttp and made sure its on Windows 10, Next go get BepInEx_X64 from the BepInEx git hub and replace the one in subnautica below zero folder then you need to download the manual install to qmods and put it steamapps/compatdata/848450 the manual install wont be in a folder just drag and drop the contents into steamapps/compatdata/848450 and then go to home /.wine /drive_c and copy the contents to steamapps/compatdata/848450/pfx/drive_c then run "protontricks --gui" select subnautica below zero then launch the game through steam.
Oh and you have to run protontricks --gui before you start the game every launch

Press Me[www.nexusmods.com] - QMod Manager

Press Me[github.com] - BepInEx

Press Me - Guide To Install Yay

Press Me[aur.archlinux.org] - Aur Page For Protontricks

Press Me[aur.archlinux.org] - Aur Page For Zenity

Note 1: Zenity for protontricks came preinstalled with my system
Note 2: Install Aur Page Stuff With Yay
Note 3: Install Winetricks With Pacman "sudo pacman -S winetricks"