[Xiaomi Poco F3 / Xiaomi Mi 11X / Redmi K40] Main3782:
You know, i'll write my own instructions. Since the Installation instructions aren't really that documented (as pixel experiences ones, for example) this is how i did it:

Make sure the bootloader is unlocked!

Installation:

1. I started with clean installing the latest MIUI. Here are the instructions to do that:

1a. Download Mi Flash Tool from here.

1b. Install the drivers. Can be done from Mi Flash Tool or Mi Unlock Tool.

1c. Download the latest MIUI ROM from here

(pick the latest one for your country that has a fastboot option, for example:

POCO F3 EEA Stable Fastboot V13.0.9.0.SKHEUXM)

1d. Download the latest firmware from here

(again, pick the latest one for your country.)

1e. Enter Fastboot mode, turn off your F3 and hold the volume down with the power button, once you see the poco logo, release the power button and when the fastboot logo appears, release the volume down button.

1f. Open Mi Flash Tool (Warning! It may crash while installing the drivers! To fix this, create a folder named "log" in the directory you launched the Flash tool.)

1g. Select the MIUI ROM folder, (extracted, it goes like this -> tar.gz -> tar -> folder, recommend using 7zip/winrar!)

1h. Select flash-all.bat, DO NOT select flash-all-lock, that will lock your bootloader. And flash!

1i. Complete the MIUI 13 Setup, DO NOT set a pin/fingerprint scanner.

1j. Enable USB Debugging. And we can finally get to flashing the rom!

2. Download platform-tools from here.

2a. Extract it and open cmd.

2b. While in the platform-tools directory, type "adb devices"

Your device should ask to enable usb debugging on this computer, click yes.

2c. Type "adb reboot bootloader" check if it detected it by using "fastboot devices" and if yes, we are getting to flashing it!

2d. Now, download the latest build and recovery from here.

2e. Flash the recovery using "fastboot flash boot <recovery_filename>.img

(replace the things i type in <> with proper file names)

2f. Reboot using "fastboot reboot-recovery"

2g. Bootloop? Doesn't work? Try using orangefox recovery. For that, you have to flash twrp. Here are the instructions:

1. Download TWRP from here. (Select 3.6.1 for proper function!)

2. Type "fastboot boot <TWRP_xxx>.img"

3. In TWRP, go to Wipe, and Format Data. Type yes.

4. Download OrangeFox from here.

5. Type "adb push <OrangeFox_recovery.img> /sdcard

6. Go to install, and install OrangeFox!

7.Reboot

3. Now, the problem is i dont know how the PixelOS Recovery is, soooo, uhhh i dunno.

4. Meanwhile OrangeFox:

1. Go to Wipe, and erase:

Dalvik, Metadata, Data, Internal Storage

2. Well again. Type "adb push <PixelOS.zip>"

3. Flash it by clicking on it.

4. MAKE SURE TO NOTICE WHAT SLOT IT SAYS. A or B.

5. Flash the firmware. Type "adb push <xiaomi-firmware>.img" and flash it.

6. After flashing, restart, if the SLOT is A, and it said B, switch to B and reboot. The same for the opposite, if it said A, and it's A, just restart.

Dirty Flashing is simple tho:

1.Boot to orangefox

2.Flash the ROM

3.Reboot

Done! This took me so long, ugh why did i do this to myself.

Also, uh you can flash magisk after the firmware or something i dont use it so i dont know the process :)