I had the unlimited plan for a few months but downgraded only to the mail plan, that way I can try different providers for VPN, Drive, and password manager.

For password manager I’ve had Bitwarden for years now and it works great for me. VPN currently with AirVPN because of easy port forwarding, and drive with Nextcloud self hosted because I can, and also works fine for me.

On KDE there’s System Monitor, which you can customize to show graphs for CPU usage and temp, among other things, and GPU usage and temp too.

For in-game monitoring there’s Mangohud, also very customizable on what you can show in the overlay