Garbee

Currently only PDF printing of the entire page view-port is available. File an issue with your use-case so the team can assess whether or not to look into including that kind of behavior.

afaik Chrome is the first browser to have Network Throttling built in in any capacity. Other browsers require you to use external tools to get anything.

Those tools also are using a chainsaw to cut bread instead of a knife. They attach to the browser as a whole, not the individual page you want.