HUGE THANKS to @soennchen for this solution!!
First of all, I recommend using T2Linux’s custom Fedora installer. It is virtually identical to the normal Fedora ISO, except it uses a patched kernel that fixes the EFI boot issues, and adds drivers for things like the touchpad and keyboard. Also, it removes the extremely loud “BONG” sound effect that plays when you start the PC up.
Here’s the solution, clone this repo, either with a USB ethernet adapter (preferred), or onto a USB drive using another computer.
Then, using a terminal, copy all the driver files to the firmware folder like so:
sudo cp /path/to/Apple-Firmware/lib/firmware/brcm/* /lib/firmware/brcm/
Now, reboot. If WiFi doesn’t work immediately after reboot as it didn’t for me, install the akmods package. Then, follow the steps in this manual (thanks @vgaetera!) to enroll the MOK key. If you are struggling to follow these instructions, here’s the quick rundown:
sudo dnf install -y akmods
sudo /usr/sbin/kmodgenca -a -f
sudo mokutil --import /etc/pki/akmods/certs/public_key.der
(when prompted, enter a password you can remember)
reboot
On reboot, you will see a simple menu. Select Enroll MOK.
On the next screen, select Continue.
Now, select Yes.
When prompted, enter the password you chose above.
WARNING: keyboard is mapped to QWERTY! (that’s the United States one)
Finally, click Reboot.
Just in case, you can run sudo akmods.
You will likely get, No akmod packages found, nothing to do. [ OK ], but that doesn’t matter.
Hooray! We should now have working WiFi! The only issue I’ve had is that apparently the WiFi seems to disrupt suspend, so the device pretty much never sleeps. Not a deal breaker for me, at least I don’t need to use a fruity OS on my laptop! There’s probably a fix for that, but I don’t know it, and it’s neither here nor there for the scope of this topic. Hope this helps!