Faster way to copy slot B back to slot A after update

I have had to do this while installing Lineage OS on my Moto X4. You can find the "copy partitions" ZIP file on the official installation site here:

Pre-install instructions

In some cases slot b can be unpopulated or contain much older firmware than slot a, leading to various issues including a potential hard-brick. We can ensure none of that will happen by copying the contents of slot a to slot b. This step is NOT optional.

To do this, sideload the copy-partitions-20210323_1922.zip package by doing the following:

1. Download the copy-partitions-20210323_1922.zip file from here.


2. Sideload the copy-partitions-20210323_1922.zip package:
   
   
   
   • On the device, select “Advanced”, “ADB Sideload”, then swipe to begin sideload
   
   
   • On the host machine, sideload the package using: adb sideload copy-partitions-20210323_1922.zip