If you are using the same MindTheGapps and you have previously flashed it to both slots, it doesn't matter if you flash it or not as long as data hasn't been wiped. At least, that's what I think is going on (I'm not an expert).
Yes, this is a side-effect of the A/B system used by the Pro1 and other modern Android devices. When you install a full OS image, it is written to the *other* slot, but add-on packages are written to the current one. You need to reboot to recovery after installing a new OS image to swap slots.
I have same touchscreen issue. Touch screen does not react as usual, randomly freezes without any reason. (Aug/30 build)
https://www.youtube.com/watch?v=48H3H5kwVIE
https://www.youtube.com/watch?v=GLLCkAqtvvY
Just wanted to provide links to source files that makes our Pro¹ keyboard. That can be used as reference for anyone wanting to understand and customise Pro¹ keyboard experience by building Lineage OS. From low to high level files we have identified the followings key components:
Device Tree Structure Include, contains GPIO pin mapping to scan codes: https://github.com/LineageOS/android_kernel_fxtec_msm8998/blob/lineage-18.1/arch/arm/boot/dts/qcom/msm8998-qrd-skuk-t5.dtsi Permalink
Driver, brings together GPIO and aw9523b controller input to define the scan codes sent to user space: h