I'm sorry, but I need more help than that. This img is OOS 10.3.9 (which is Android 10) and the LOS I have installed is 18.1 (which is Android 11) so I need to be sure that flashing an OOS img based on Android 10 will be safe to do as all guides I've found say its best to flash an img based on the same Android version already installed.
Also, I can't find an up-to-date guide on returning to stock using TWRP (or any other method for that matter). Can you please provide me with a link to one? Thank you.