I've been thinking about this as well, after using a manual version of this strategy. Might still implement it one day.

That said, it's pretty hard. It's not entirely clear which data points Facebook uses, but it's very likely you can't influence all of them. For example, friends adding you as contacts, or linking your profile to your phone number. If you also want to continue using it as normal, your normal usage will still give a lot of data about what you view; what you interact with; when you use it; that might stand out from the random stuff - and if you don't want to continue using it as usual, the extension will have to visit the website by itself, without interfering with your regular browsing activity, and without relying on your computer being on.

I also think that if something like this would get big enough to actually impact the quality of their algorithms, it'd be pretty easy for Facebook to detect abnormal activity.

(And of course, it's not even that much of a problem if the algorithm screws up more often, as long as advertisers believe it's accurate.)