[Google Pixel 2 XL ROMs, Kernels, Recoveries, & Oth] GROOVYJOSHCLARK:
I would do it like this and yes updater works but keep in mind, once you OTA update, you will lose ROOT and/or kernel so those will need to be repeated. I changed the order slightly (kernel/ROOT), last 2 steps:

1. D/L on host computer: ROM.zip, LOS_recovery.img and nanogapps.zip (no LOS_recovery.zip).

-lose LOS recovery you dont really need it, but I know you asked about it, use it if you want to but its not needed

2. Reboot to the BL: "adb reboot bootloader"

-This only works if ADB debugging is enabled, I prefer to power down, hold down volume + power, this lands BL

3. Delete the encrytion/userdata via fastboot "fastboot format userdata".

-I always format /data and wipe all partitions except the last (storage I believe)

4. Temporarily boot into the recovery via "fastboot boot recovery.img".

-correct

5. Install the ROM within recovery. Sideload ROM.zip via: apply update> apply from ADB and on the host: "adb sideload ROM.zip".

-Dont bother sideloading, use TWRP's GUI and install, select ROM

6. Reboot to bootloader then fastboot recovery via "fastboot boot recovery.img".

-Correct but just reboot to BL from TWRP

-At this point I redo the wipes, all partitions except the final (storage), along with /data and then push the files again and reinstall the ROM, I do this because /vendor errors until you either ADB install the vendor partition, OR you let LOS install the ROM and update the partitions (/vendor is one of them) so I like it clean and dont mind the extra few minutes it takes, this is optional.

7. (Optional) Install nanogapps within recovery. Sideload nanogapps.zip via: apply update> apply from ADB and on the host: "adb sideload nanogapps.zip".

-This really sort of optional, sure you can run without Google Framework (Google Apps) but why would you if you use anything Google related (like GMail/Google Drive/ETC)? Why use sideload, just use TWRP once you have installed the ROM, then rebooted to BL, then ADB TWRP, you are good to go with GAPPs and TWRP is the easiest way (but you can sideload if you like it better). Reboot to BL, ADB TWRP

9. (Optional) Flash kernel/recovery/root/reboot system

8. Reboot system / recovery> reboot system now.

Personally I like to install MAGISK, and patch the BOOT.IMG but this needs to be pulled from the ROM .zip then python extracted using payload scripts, so its up to you. You can take OTA's, I did it this morning with this same process and now I am running Oct LOS, BUT I had to redo my ROOT, and KERNEL as this is lost with the OTA. You can find the full guides on how to python out the boot.img and patching with MAGISK earlier in this forum or others for the Pixel 2 XL. I laid it out a few times, but I dont recall where and when but its there.

Once you are in the OS, go into MAGISK (assuming you installed the app), then settings, MAGISK hide enabled, then with ROOT, remount /system as RW, go to /data/adb/service.d/ create new empty file, and give it 755 permissions with only this in the file (call it cts.sh):

#!/system/bin/sh

resetprop ro.build.version.security_patch 2020-08-05

Save it and reboot, then test safety.net, you should pass, but not until you do both things (create the script file and give it the right permissions, ALONG with MAGISK hide), then you will pass.