SharePoint Online Performance. Easy Way to Capture Metrics

I've stumbled across an interesting Chrome Extension Page Diagnostics for SharePoint Chrome extension. It shows some useful info on the page performance.


Microsoft Article "Use the Page Diagnostics tool for SharePoint Online"

In my case SPRequestDuration and SPIISLatency were not displayed, but you can get these values by simply pressing F12 and typing g_iisLatency and/or g_duration in the console:
g_iisLatency - Shows network latency between the client browser and the IIS server
g_duration - Shows the time it took the page to be returned to the client browser

Update:
I've found out that g_iisLatency and g_duration only show up in the classic pages.