Before I attempted to setup Librelec on my new Pi 5 I did a lot of searching and found a lot of misinformation, so I wanted to post how easy it was.
I purchased a Geekworm X1001 PCIe M.2 Key-M NVMe SSD PIP PCIe Peripheral Board from amazon. installation was a snap. I already had a compatible 512gb m.2. and a case designed to fit.
I installed Raspberry Pi os 64 to the SD card, and booted into it. M.2 drive showed up without any additional work.
I used the imager to image the m.2 with Libreeelec.
I ran the command "sudo rpi-eeprom-config --edit" from the command line and changed the line BOOT_ORDER=0xf41 by adding the number 6 to the end, making it
"BOOT_ORDER=0xf416"
Then I rebooted right into Libreelec.
That's it. No other config changes. And it's been working beautifully. Yes it needs the sd card to tell it to boot to the M.2, but so what? The only real issue is the Pi's inability to handle Youtube videos that are 4k/60fps or higher due to Youtube's use of the VP9 codec instead of h265. Pi simply cant handle the decoding fast enough, but that's mostly Youtube's fault. Everything else plays beautifully (even over the network).
Thank you Libreelec Developers, you guys are awesome!