Did you read the article? It captures screenshots, doesn't matter if you use a Shield, console or whatever.

I've had cases where a game crashed and I couldn't open any other window including the task manager. I could alt tab to it, but when I try opening it it would instantly revert back to the crashed game. But if you move task manager to another desktop and switch to that desktop, you can force close the crashed game. Pretty much a fringe case and I've never found another reason to use this feature personally.

Aegis can do automatic encrypted backups to a cloud provider or locally.