Not OP. I'm dual booting Windows and Fedora. Fedora supports secure boot, so everything works out of the box. The only thing that annoys me are the Nvidia drivers. Those need a kernel module that you need to compile yourself. And all kernel modules need to be signed for secure boot.

In theory, it's still easy: At first, Fedora boots with a precompiled and signed nouveau driver, that supports secure boot - so you can use your PC after the install. When you install the NVidia Driver, akmods etc gets setup automatically. Also they automatically generate a key pair for you and mokutil allows you to send that key to your UEFI, so that you can install it on the next boot. So it's just reboot, load the key once in the UEFI and after the reboot the official driver is running. After every kernel upgrade akmods should automatically recompile the module, sign it with your key (now known by your UEFI) and it just works.

In practice... For me it's a 50:50 if the akmods auto build works. So, after a kernel upgrade, I usually reboot, wait for the build to fail to a Desktop in 1024×768 and then have to open a terminal and type akmods --rebuild --force. After the build and an additional reboot everything works again.

Lmfao it's a piece of shit, basically I have all three of my drives hanging out of the 5.25 bay on the front of my machine. That way I can easily unplug my 2 Linux drives when I enable secure boot. Otherwise my Linux won't boot, which fucking sucks to fix. So basically it's a pain in the ass and BF6 just isn't good enough for me to spend that effort.

Some distros like Mint support ‘secure boot’ out of the box, so dual booting works fine without any extra work. But I haven't used Nvidia drivers yet, so idk about that.