[Redmi Note 11S 4G / POCO M4 Pro 4G (fleur)] der_brain:
With "fetching" I meant downloading from the links provided in your guide for method 1.

Anyhow, I can't get SP Flash to connect to the device (in BROM mode). I installed all the drivers from here, and while holding all 3 buttons, I can only see a MediaTek USB COM device connecting and disconnecting again and again (always showing up with a yellow alert symbol, indicating it's not working correctly). Finally SP Flash gives up to connect with a timeout.

The only thing I could achive was setting up the MTK-Client from a different folder of the same sourceforge repository: https://sourceforge.net/projects/fleur/files/UNBRICK/MTK-Client/

After starting the mtk_gui, and a couple of cycles of connecting/disconnecting the COM device, the connection seems to be established, and now a "UsbDk device" shows up in the device manager instead of the COM device.

And the MTK Client is showing these debug messages:

[22:09:23]: Loading payload from mt6781_payload.bin, 0x264 bytes
[22:09:23]: Kamakiri / DA Run
[22:09:23]: Trying kamakiri2..
[22:09:23]: Done sending payload...
[22:09:23]: Successfully sent payload: C:\Temp\mi\mtkclient-main\mtkclient\payloads\mt6781_payload.bin
[22:09:23]: Device is protected.
[22:09:23]: Device is in BROM mode. Trying to dump preloader.
[22:09:24]: Failed to patch preloader security
[22:09:24]: Patched "get_vfy_policy" in preloader

...with nothing else I could do.

And this was printed to the console:

C:\Temp\mi\mtkclient-main>C:\Users\Admin\AppData\Local\Programs\Python\Python311\python.exe mtk_gui
Preloader - Status: Waiting for PreLoader VCOM, please connect mobile
Port - Device detected :)
Preloader - CPU: MT6781(Helio G96)
Preloader - HW version: 0x0
Preloader - WDT: 0x10007000
Preloader - Uart: 0x11002000
Preloader - Brom payload addr: 0x100a00
Preloader - DA payload addr: 0x201000
Preloader - Var1: 0x73
Preloader - Disabling Watchdog...
Preloader - HW code: 0x1066
Preloader - Target config: 0xe7
Preloader - SBC enabled: True
Preloader - SLA enabled: True
Preloader - DAA enabled: True
Preloader - SWJTAG enabled: True
Preloader - EPP_PARAM at 0x600 after EMMC_BOOT/SDMMC_BOOT: False
Preloader - Root cert required: False
Preloader - Mem read auth: True
Preloader - Mem write auth: True
Preloader - Cmd 0xC8 blocked: True
Preloader - Get Target info
Preloader - BROM mode detected.
Preloader - HW subcode: 0x8a00
Preloader - HW Ver: 0xca00
Preloader - SW Ver: 0x0
Preloader - ME_ID: 21F9470AFA936D46FEF87FE843174527
Preloader - SOC_ID: 3DFDC5772241B347992FE396679742F6EDB329082986385DDBE38D0BA78D152A
Preloader - Status: Waiting for PreLoader VCOM, please connect mobile
Port - Device detected :)
Preloader - CPU: MT6781(Helio G96)
Preloader - HW version: 0x0
Preloader - WDT: 0x10007000
Preloader - Uart: 0x11002000
Preloader - Brom payload addr: 0x100a00
Preloader - DA payload addr: 0x201000
Preloader - Var1: 0x73
Preloader - Disabling Watchdog...
Preloader - HW code: 0x1066
Preloader - Target config: 0xe7
Preloader - SBC enabled: True
Preloader - SLA enabled: True
Preloader - DAA enabled: True
Preloader - SWJTAG enabled: True
Preloader - EPP_PARAM at 0x600 after EMMC_BOOT/SDMMC_BOOT: False
Preloader - Root cert required: False
Preloader - Mem read auth: True
Preloader - Mem write auth: True
Preloader - Cmd 0xC8 blocked: True
Preloader - Get Target info
Preloader - BROM mode detected.
Preloader - HW subcode: 0x8a00
Preloader - HW Ver: 0xca00
Preloader - SW Ver: 0x0
Preloader - ME_ID: 21F9470AFA936D46FEF87FE843174527
Preloader - SOC_ID: 3DFDC5772241B347992FE396679742F6EDB329082986385DDBE38D0BA78D152A
Port - Device detected :)
DAXFlash - Uploading xflash stage 1 from MTK_AllInOne_DA_5.2136.bin
xflashext - Patching da1 ...
xflashext
xflashext - [LIB]: ←[33mError on patching da1 version check...←[0m
xflashext - Patching da2 ...
DAXFlash - Successfully uploaded stage 1, jumping ..
Preloader - Jumping to 0x200000
Preloader - Jumping to 0x200000: ok.
DAXFlash - Successfully received DA sync
DAXFlash - UFS Blocksize:0x1000
DAXFlash - UFS ID: MT128GAXAU2U22
DAXFlash - UFS MID: 0x2c
DAXFlash - UFS CID: 2c014d54313238474158415532553232
DAXFlash - UFS FWVer: 30313031
DAXFlash - UFS Serial: 3a2020200000000000000000
DAXFlash - UFS LU0 Size: 0x1dcb000000
DAXFlash - UFS LU1 Size: 0x400000
DAXFlash - UFS LU2 Size: 0x400000
DAXFlash - DRAM config needed for : 2c014d54313238474158415532553232
DAXFlash - Sending emi data ...
DAXFlash - DRAM setup passed.
DAXFlash - Sending emi data succeeded.
DAXFlash - Uploading stage 2...
DAXFlash - Upload data was accepted. Jumping to stage 2...
DAXFlash - Successfully uploaded stage 2
DAXFlash - UFS Blocksize:0x1000
DAXFlash - UFS ID: MT128GAXAU2U22
DAXFlash - UFS MID: 0x2c
DAXFlash - UFS CID: 2c014d54313238474158415532553232
DAXFlash - UFS FWVer: 30313031
DAXFlash - UFS Serial: 3a2020200000000000000000
DAXFlash - UFS LU0 Size: 0x1dcb000000
DAXFlash - UFS LU1 Size: 0x400000
DAXFlash - UFS LU2 Size: 0x400000
DAXFlash - HW-CODE : 0x1066
DAXFlash - HWSUB-CODE : 0x8A00
DAXFlash - HW-VERSION : 0xCA00
DAXFlash - SW-VERSION : 0x0
DAXFlash - CHIP-EVOLUTION : 0x0
DAXFlash - DA-VERSION : 1.0
DAXFlash - Upload data was accepted. Jumping to stage 2...
DAXFlash - DA Extensions successfully added

I'm really quite frustrated not to get any further. And I'm not really unexperienced - I'm a developer, though not in the mobiles/Android area...

In-between, I also found a way of button combinations to put the device in fastboot mode. (During the Safe Boot procedure I could power it off using all 3 buttons, and once the battery charging symbol it displayed, the volume down + power combination works to enter fastboot.)

Anyhow, I assumed, this is a dead end, as fastboot requires an unlocked bootloader (at least I read it somewhere).

And now finally, obviously after the MTK-Client did something during the connection setup, the device is now constantly rebooting every few seconds - so no way to stay in the recovery of fastboot mode anymore. :-(

Any ideas?