I used the process as detailed on the LineageOS site, making mods to the filenames, of course, although I did flash Lineage first - https://wiki.lineageos.org/devices/pioneer/install
The main issue was with the correct drivers for the XA2 itself - none of the documentation from e/Lineage was of use. Installing the ADB and Fastboot drivers was fine. It was the drivers for the XA2 itself that defeated me for quite a long time, because it was not possible to see the phone during fastboot mode. “Fastboot devices” returned nothing
Eventually, I found some documentation at the SailfishOS site, which finally allowed me to flash Lineage and then /e/.
That docco is worth linking here: https://jolla.com/sailfishx-windows-instructions-xa2/
The driver listed as “Sony sa0114” will allow the phone to be seen during Fastboot mode. None of the drivers in the e/Lineage docs were useful, in my experience.
BUT, it is necessary to install this in the very specific way the Sailfish docs say.
Viola! Phone was visible in Fastboot, and could be flashed. But it was a bit iffy. The Mar 10 image just kept giving me an endless bootloop, until the system locked and I had to reflash the original Sony ROM to start the process all over again using their “Emma” flashtool.
Once installed, the Feb 28 image allowed me to upgrade over the air to the newest images. So far so good. OtA of Mar 14 image has also worked.