Bazzite might not install printer-driver-brlaser by default. If you ran rpm-ostree install printer-driver-brlaser in a terminal what does it say? If you get an "already provided by" error than disregard this but, if it does install it then reboot.

That guide is definitely not going to work on Bazzite.

I'm on Fedora Silverblue and that package is installed by default. My printer (HL-2395DW) was automatically detected and required no configuration.

Run efibootmgr and find out. You can also delete the old/obsolete entries without having to go into the UEFI settings.

So, quick testing is that mpv will pull subtitles by default but not display them without cycling the track (with J) or setting slang with an available language code[s]. (with slang=en,en-US for English.) Although, it will completely ignore auto-generated subtitles.

I did find that ytdl-raw-options='sub-langs="en,en-US",write-sub=,write-auto-sub=' will also give the option to use auto-generated subs.

I'm not too familiar with SMPlayer but I was seeing that you can use an mpv.conf with it.

You can layer packages not in the base image. This effectively installs that package. Except by default the "installation" will not take effect until the next boot.

If you layer packages with rpm-ostree, they are not temporary. Although, I would try to keep it to only things in the distros default repos because dependency issues will just cause updates to no longer apply.

On Linux, it is just more important that guides be written for the distro you are using or at least related ones. So, more popular long-standing distros just end up with more guides or better documentation.