Does anyone know if it's possible to download a stand-alone El Capitan installer? Or even capture the download when it is being installed via the App Store?
AFAIK, there is no such thing as a stand-alone installer.
But, after one has downloaded El Capitán, a splash screen appears asking if you want to continue/install it, etc. STOP!
At that point, look in your Applications Folder for a file called "Install OS X El Capitan", for it is that file which may be copied to a thumb drive, etc.
If you don't copy it then, but proceed, the installer will delete it when the installation has been completed. Ergo no installer left to copy.
