[Thinkpad Tablet Android Development] snickle:
None of this is my work, just the steps to get it to run for me.

The steps are fairly step by step and some seem redundant, but they work. I had lots of failures.

Start with TWRP and Magisk Installed

Note: This will process will complete erase device, so make sure google backup is up to date and using titanium (or something else) for any other backups.

Download the following files and copy to sdcard

Device ID

Device ID.apk | by xda-developers.com for Utilities

Download GApps, Roms, Kernels, Themes, Firmware, and more. Free file hosting for all Android developers.

androidfilehost.com

Nikgapps

https://sourceforge.net/projects/nikgapps/files/Config-Releases/NikGapps-R/24-May-2021/NikGapps-emriza-myfav-arm64-11-20210524-signed.zip/download

Force Decrypt

Disable_Dm-Verity_ForceEncrypt_11.02.2020.zip | by Droidwin for Utilities

Download GApps, Roms, Kernels, Themes, Firmware, and more. Free file hosting for all Android developers.

androidfilehost.com

TrebleGSI Image (Make sure to extract image from xz file)

https://sourceforge.net/projects/treblerom/files/crDRom11/2021.05.21/crdrom-v308-210521-arm64-bvZ-lite.img.xz/download

Latest Magisk APK (Make sure to change extension to .zip)

Reboot to recovery

Goto Wipe

Format Data

Advanced wipe - Select System and wipe

Install cdrom-c306-210428-arm64-bvz.img to system

Reboot recovery

Install Disable_Dm-Verify_ForceEncrypt_11.02.2020.zip

Install Magisk zip

Install Disable_Dm-Verify_ForceEncrypt_11.02.2020.zip

Reboot system

Press and hold power button when Eye icon shows up. Select restart - Recovery

Goto Wipe

Format Data

Reboot recovery

Install Magisk zip

Install Disable_Dm-Verify_ForceEncrypt_11.02.2020.zip

Install NikGapps-R/24-May-2021/NikGapps-emriza-myfav-arm64-11-20210524-signed.zip

Reboot system

Click start

Skip Mobile network

Select and login to wifi

On Copy apps & data click next

Select a backup from cloud

Enter PIN

When you get "This device isn't Play Protect certified" select "Got It"

Click More and accept through google services

Select Face unlock + PIN

Enter PIN twice

Setup Face lock

Click Done

Click Next

Click Skip

Click Start

Ignore Play Protect errors

Setup sdcard as portable storage

Install Device+ID.apk from sdcard

Open Device ID and accept permissions

On PC goto https://www.google.com/android/uncertified/ and enter GSF.

Wait 2 minutes - PLEASE!!!

Reboot

Goto Settings - Accounts

Add your google account.

Either restore from account setting or wait to be prompted to finish setup. This will restore apps, contacts, etc.

When Setup complete run Magisk and complete its setup.

In Magisk, enable MagiskHide and Hide Google Play Store

Run safetycheck. It should fail.

Load module MagiskHide Props Config

Reboot

From terminal window (I use TermUX),

Run:

su

props

Select 1

Enter fingerprint value: Lenovo/LenovoTB-X606F/X606F:10/QP1A.190711.020/TB-X606F_USR_S300177_2103041623_V9.56_BMP_ROW:user/release-keys

b to go back

4 for custom props

n for new custom prop

Property: ro.build.version.security_patch

Value: 2021-02-05

e to exit

Reboot

Go to magik and rerun safetycheck. It should pass and restricted apps now available in store (Disney, Netfilx, etc.)

Update apps in Play Store

Setup tablet to your preferences

Good Luck.