Here is an updated version of TWRP for Mi Pad 3 (Codename: Cappu). This is the latest update based on TWRP v3.2.1-0 I used TWRP by Multirom and rakomancha's TWRP as base for a working device / twrp tree for our device. I have tested this version for some hours and discovered no errors - but tell me if you find some. If you are looking for a tree for your Mediatek MT8173 / MT8176 device you can use my one as base. You should also have a look at the twrp main-thread for all neccessary changes that need to be made.
This image has only been successfully tested by me at this point.
Please exercise caution and care when attempting to flash anything to your device.
You are completely responsible for any possible issues or damages resultant from undertaking the following procedures.
That being said, this image and method should be safe.
1. Open Settings -> About Phone -> tap 5-7 times on Miui Version to activate Developer Options.
2. Open Settings -> Advanced Settings -> Developer Options and activate USB-Debugging.
3. Turn your Tablet off.
4. Extract SP_Driver_V1524.zip on your Windows PC with (7zip) and install drivers.
5. Extract SP_Flash_Tool_exe_Windows_v5.1720.00.000.zip on your Windows PC with (7zip).
6. Download twrp-3.2.3-0-cappu-20180906.img and MT8173_Android_scatter.txt.
7. Open the folder SP_Flash_Tool_v5.1620_WinSP_Flash_Tool_exe_Windows_v5.1720.00.000 and run flash_tool.exe.
8. In SP Flash Tool open the file scatter (MT8173_Android_scatter.txt) with the yellow button on the right (Scatter-loading).
9. Uncheck all boxes, except "Recovery"
10. Press the green (DOWNLOAD) Button. After that plug your usb cable into Mi Pad 3 and wait until SP Flash Tool says FINISH!
11. TRWP was flashed successfully and is now ready to use. Turn the tablet off. Hold Volume(+) and Power Button until you see TWRP Menu.
1. Install Minimal ADB and Fastboot -> https://forum.xda-developers.com/showthread.php?t=2317790
2. Open Settings -> About Phone -> tap 5-7 times on Miui Version to activate Developer Options.
3. Open Settings -> Advanced Settings -> Developer Options and activate USB-Debugging.
4. Turn the tablet off. Hold Volume(-) and Power Button until you see Mi Bunny / Fastboot.
5. Plug your usb cable into your Mi Pad 3.
6. Open cmd window in Windows and browse to Minimal ADB and Fastboot folder.
7. Download twrp-3.2.3-0-cappu-20180906.img and copy to Minimal ADB and Fastboot folder.
8. Type in cmd window: fastboot flash recovery twrp-3.2.3-0-cappu-20180906.img. If successful, reboot and hold Volume(+) and Power Button until you see TWRP.
To get Root access, flash this Latest version of Magisk. You can find the downloads and a guide here.
twrp-3.2.3-0-cappu-20180306.img 2018-09-06 Update: TWRP 3.2.3-0
TWRP Tree on Github: https://github.com/Goayandi/android_twrp_xiaomi_cappu