[Redmi Note 10S] XSOARER:
This is a post in progress. For reference and may not be important at all but I have a Poco M5s 8/256 GB, MTK G95 8-core @ 2.05 GHz. It currently runs Android 13 TP1A.220624.014, MIUI 14.0.4.0 (TFFMIXM). My Poco M5s is model 2207117BPG with baseband MOLY.LR13.R1.MP.V89.6P64 and kernel version 4.14.186-perf-geeec8719f23a. This Poco was sold in latinamerica. It was only rooted with Magisk.

PREFACE. FOUR VERY IMPORTANT NOTES:

You should have unlocked your bootloader first for all this to work. There are two methods to do it. The official method and the instant method. It's easier for anyone to use the official method. If you are a tech literate, try the instant method.

It is impossible to downgrade to MIUI 12. Flashing a fastboot image lower than MIUI13 leads to bootloop. Then the phone is bricked and can be restored only in EDL mode. This makes most custom roms incompatible, as they target MIUI 12.5. (@jcd000 dixit)

This phone can't download and boot a kernel file (*.img). This is, you can't fastboot boot recovery.img or fastboot boot boot.img. You necessarily need to flash anything you want to boot into a boot partition (boot_a, boot_b). This is why you need to have a backup of your original boot.img (kernel) always handy (I have it in the external SD). And/or, if you use magisk, you may want to also have a magisk patched boot.img always handy.

This device does not have a recovery partition, maybe this is the case for all A/B devices, I don't know.

FLASHING A CUSTOM RECOVERY

If you already unlocked your bootloader, you can enter into fastboot mode. You'll know you are in fastboot mode because the word FASTBOOT will be on the display.

Using hardware keys: keep both volume keys pressed and turn on your phone keeping the power button pressed simultaneosly.

Using the command adb reboot bootloader (this method implies you already activated USB debugging and installed the adb executable)

For this step, you'll need to have the fastboot executable configured in your PC, you need to connect your phone using a USB cable to the computer with the fastboot executable.

Download the attached vbmeta.img file. This is a blank img file that contains nothing. It's easier if this file is in the same location that your fastboot executable is.

Run the command "fastboot flash vbmeta vbmeta.img". If you are in Windows, Shift+RIght Click in a blank space in the file explorer in this location will give you an option to open a command terminal or console.

Now download the attached recovery file "OrangeFox-Unofficial-rosemary.img". In this case, I'll share an OrangeFox build that was shared to me as a tester. Use this under your own risk. It is compatible with Android 13, this is very important for us. We need to check if our recoveries are compatible with the Android versions we intend to use. Needless to say, you can use whatever recovery you feel comfortable using in this step. Put this file in the same folder you used for vbmeta.img to keep things simple.

With your phone in fastboot mode, run the command "fastboot flash boot OrangeFox-Unofficial-rosemary.img". Again, you can change the recovery image you want to flash. The terminal must inform you which boot partition will be affected. As a recommendation, don't loose track of this.

Now reboot into recovery.

Run the command "fastboot reboot recovery", or

You can turn the phone off and turn it on with the Vol+ key pressed simultaneously.

If everything is going well, a horrible Orange screen will display a stilized white fox and after this you'll probably find the file structure of your sdcard. But we are not done yet.

Now it's time to use your original boot.img or magisk patched from the original boot.img that you saved to keep it handy.

In the OrangeFox interface, look for the original boot.img file. If you put it in the sdcard then go to /sdcard1. Select it, choose the Boot partition and Swipe the big orange slide to flash the original boot.img into its corresponding partition. Do not activate "Flash to both slots".

After a Succesful image flash of Boot go back. Tap on the Hambruguer Menu (the three horizontal lines), tap on More..., and tap on the Flash current OrangeFox option. Swipe the big orange slide to confirm.

This will take some seconds while the boot image is patched. After a successful process, we are done for good. We can go back and reboot the system. Each time we want to go into recovery, we'll find OrangeFox now.

I want to continue this post flashing a custom ROM. I'm currently testing LineageOS 21 (Android 14 based) but, while it flashes rather easily with OrangeFox and LineageOS recovery, it just won't pick any signal from the SIM cards. It boots and works awesome, very promising stuff. So, hopefully, I will continue later with this guide.