I have used wine under ubuntu linux, and tried it under Arch based linux, it sounds like you have calibre installed but calibre you don't need to use wine for calibre itself, since
calibre has linux binary's or using apt-get install calibre on ubuntu, arch you can install calibre with
https://snapcraft.io/install/calibre/arch
https://calibre-ebook.com/download_linux
for Kindle Previewer and kfx plugin you install kfx plugin just like you do on a windows platform, but for kindle previewer 3 you do have to download the installed and like in command promplt you have to use a terminal on linux to run wine with the installer but once its installed from my experience with linux the linux version of calibre should be able to use wine and run the kindle previewer to make an kfx format, I had it working, but I have used linux for a few years and also use windows which windows is a lot easyer to use, but if you prefer linux or can't run windows 10 or windows 11, but getting calibre and kindle previewer working, then getting your kindle paperwrite working under linux can take a little or a lot more work to get right, its not as easy as using calibre from windows itself, in any case good luck, I stopped using linux dual booting with windows 10 or win 11 which I am currently using because it would miss up my local computers desktop's clock between the two Operatiing systems, in any case, I don't recommend trying to run kindle previewer under wine but it can be done,
I just don't know for sure how stable it is with the linux port of calibre software, which depends on which distro of linux you are trying to run, since there is a lot more operating systems under linux bases which each one requires you to do different commands to install software, its not for beginners that are not skilled in software like linux, but if your not new to linux that its a lot easyer to fix stuff like that, anyway again
I hope that helps, also I never ran unraid on linux
and the term docker refers to apps like on the mac operating system basically they are app trays that launch the software titles, like in kde plasma 5 or gnome shells, a docker is a app that runs and launches apps like how windows has its star menu and icons but a docker happens to be more in the style of the mac OS dockers that do the same type of thing but on Linux. I think when he refers to (unraid docker or term of that) the person writing may be talking about something like 7 zip or unzip but as a app with compression instead of the executable file maybe got that one confused maybe.
the other reason I stopped using Linux is because last time I tried arch Linux on my gigabyte motherboard, it did something strange to my motherboards bios, I had to reinstall my gigabytes dual bios, because the start up of the bios itself started running slower than normal, when I refreshed or reinstalled the bios from windows it fixed it and now its booting up windows normally again, but something in Linux was causing grub 2 boot loader for the menu that has both windows and linux defaults to linux unless you change that to load slower than normal but again my desktops problems were fixed by removing Linux in any case it started to have a delay on the arch port of linux on my desktop, that when I figure out I needed to reinstall the bios from the software at gigabytes website for F12 ver. bios which it uses, I have two hard drives in it and had windows 11 on hda 1 drive, and arch linux on hdb 2 drive but something was causing some problems or somehow the bios got cruppted also was using secure boot for awhile, but turned it back on after removing Linux, I think I had to turn it off in order to use Linux with my desktop without problems, but again my bios was last updated in 2013, and gigabyte has not release any updates for it, I do use a RTX 2080 3D card but again my motherboard is a few years old but it can handle windows 11 fine with its current patches it helps the start up , again sorry I got off topic, but that my reason at this time for stopping my use of Linux, otherwise maybe I could of better help with the matter of wine and kindle previewer not working correctly, or if simple you didn't have kindle previewer installed the logs in calibre would show under linux problems with wine and kindle previewer not working of course it needs to be installed, which I think is it correct on your linux system?