Just In case anyone is interested I have pushed HTOP 2.2.1 to github, so it is possible to monitor big.LITTLE cores in real-time.
You can view the big.LITTLE in action, Vcore, Cpu thermal throttling and Cpu frequency for each big or LITTLE core.
HTOP is a nice console graphical tool for system-monitor, process-viewer and process-manager.
DEB package and source code in case you want to extend or fix things.
Be aware the process list and task can be very intrusive if you