Lesson: Never check for updates after the second week of the month.
Checking for Windows Updates after the second week is no different if you download AMD "Optional" driver or Nvidia "Hotfix" Drivers. These are BETA Window Update fixes for issues that are occurring before Patch Tuesday.
As mentioned in the article, these BETA Updates will eventually be part of Patch Tuesday Updates if not install before. As mentioned, these are "Validated Production Quality Optional Updates".
These Optional Updates are Non-Critical Updates. It is made Optional so that Users won't need to Reboot the computer more than once a month.
So, if your Windows OS is having some issues and you learn there is an Optional Windows Update for an immediate, hopefully, fix - then you can click "Check for Updates" to download the fix until the next official Patch Tuesday.
The majority of the Users will probably wait until Patch Tuesday to let Windows Update download any new updates available.
So, In my honest opinion, there is nothing wrong to download a Windows Update after the second week if you have heard that Microsoft has an Update to fix a Windows issue that you are having.
Yes and Optional in most cases doesn't really mean optional. Ultimately it's typically best to install any updates. Can't say how many times I have seen issues trace back to updates that got hidden and not installed or just not installed.