>> by being able to mark tabs as "no background activity allowed"
> What if you spent a few hours filling out some government form online, then you went and took a break by watching a few YouTube videos? Memory usage might spike up, and the browser decides to unload the tab with the form. You'd be mad if form state got lost when you switched back.
GP is talking about actively marking tabs as "no background activity allowed".
I have been searching in vain for something like that: stop scripts in background tabs except for specifically whitelisted pages.
There is absolutely no reason that I can see why every website and their ads should be allowed to roam around freely in the background.
There is however a number of reason why they should not be allowed. Battery life and phishing attempts readily comes to mind.
I guess whoever comes up with a well-working extension for that can easily ask me for USD 30 or even 40 and expect me to be a walking billboard for it ;-)