Every time I hear about a terrifyingly invasive means of "improving performance" its targeted at developers. Is it just selection bias, or does the world actually hate us?
Mostly because they are a newer profession and a trickier one to quantify.
Time and motion studies, along with 'scientific management' were already a serious hit in terrifyingly invasive performance enhancement for blue collar labor around the turn of the 20th century(Taylor and the Gilbreths being the poster children, with many successors). The workers who haven't been replaced by robots yet are likely still subject to a descendant of it. Though less amenable to automation, service sector jobs are also rationalized more or less as tightly as available technique allows.
Software development is still a work in progress because it only started existing comparatively recently and because it takes more technology to dismiss any "Oh, what we do here is unquantifiable skilled craftsmanship" positions.
It is selection bias, in that you apparently haven't heard of it happening to basically everyone it can reach; but the world does actually hate you, and is actively working on making software development absolutely as soul crushing as seems economically desirable.
So, a canvas randomizer is needed, isn't it? Or a means to get many, many machines to all appear identical.
Unfortunately, since this technique is almost certainly being used alongside a suite of others, it's tricky to know what tactic is most privacy-maximizing. Canvas randomization would ensure that your browser's canvas fingerprint does not remain stable; but if the attacker is able to determine that you are randomizing(by making multiple runs, possibly even from different domains, that ought to be identical but won't be if your canvas is randomized), that may also be a behavior distinctive enough to be useful.
Interestingly at least AT&T (and probably other telcos as well) will refuse to provide the ANI logs for calls like this. They act confused when you ask then ask a supervisor and say its against policy to give customers the ANI info for incoming calls. It's almost like they want to protect the robocallers.
Pink contract, anyone?
After an instrument has been assembled, extra components will be found on the bench.