I have never said that I don't allow Windows Updates to install on-line. When I make install DVD media is when feature upgrades are involved such as the May 2020 feature upgrade. Normal monthly updates I allow to go through the normal Windows Updates.
As to your direct questions...
BB wrote:
(1) What is the benefit of doing it like you do vs letting Microsoft download and install directly?
Remember that this only applies to feature upgrades, spring and fall. Largely this is just personal preference but, I think, has advantages. Say that I'm in the middle of a feature upgrade and my internet drops and the upgrade fails. What havoc could this possible cause? To be honest I don't know. My actual guess is that the upgrade would just fail and revert back to the current running version of Windows. I just feel more comfortable doing it this way.
BB wrote:
(2) What are the exact steps you follow once Microsoft announces that an update is available? Do you first download an ISO file; if so, where do you get this file? And does this ISO file contain all of Win 10, including the new updates, or does it contain only the updated portions of Win 10?
If it is just a monthly update I just tell Windows Update to download and install by clicking 'download' on the update dialog. Remember that I have Windows Updates set to notify instead of automatic. It takes a registry hack to do this.
As to feature upgrades, such as the May 2020 upgrade, I go to the following link:
https://www.microsoft.com/en-us/software-download/windows10and select to 'Create Windows 10 installation media'. I download and install the tool and run. Under the options I choose to create media and select to do an .ISO download which I then burn to DVD. I then install the feature upgrade from the install DVD I made.
You have to understand that there is a difference between a monthly Windows Update and the spring/fall Feature Upgrades. Feature upgrades actually re-install Windows with a new version while monthly updates just fix security issues and current bugs.