To stop the installation of KB4056892, I was able to catch the installation while its percentage was still increasing - that is, before it requested a restart. Fortunately, I was able to start by applying a backup of Windows that was captured at a time before the start of the installation. I tried several iterations of trying to catch it until I succeeded.
As for the discrepancies in the list of pending installations, I do not have an answer for you. It must be a Microsoft "secret". After you informed me of the differences, I checked my own list and also noticed differences. After I manually checked for updates, one of the items in the list (Defender) appeared, installed and then "disappeared". The other items are still under the radar and have not installed yet. It may be that these items are being listed for download, but have not been acquired. Obviously, this is just a guess and not very useful.