To update without wiping data, you can follow the OP post here
Caution: I originally wrote this guide when it was necessary to disable verity and verification before flashing patched boot.img. Now Magisk has overcome this requirement and some users have reportedly flashed updates without disabling...
1. Modify flash-all.bat:
Open flash-all.bat in notepad and remove -w and add --disable-verity, -- disable verification and --skip-reboot to the fastboot update line. After editing, it should read as:
fastboot --disable-verity --disable-verification update image-raven-xxxxxxxxxxxx.zip --skip-reboot
2. add the following commands to the bottom and change the img name to your patched boot image
ping -n 5 127.0.0.1 >nul
fastboot flash boot --slot=all magisk_patched-23xxx_xxxxx.img
Once the script is ran, you should now be updated to the latest version with Magisk boot image installed.