>>reacto+(OP)
This is a level or two below where my knowledge of the browser trails off, so I'll ask generally: how would this interact with things like the WebKit Content Blocker API?
>>eroppl+hb
Most likely all extensions and content blockers would be disabled for DRMed sites. Or maybe they'd be enabled but the browser would tell the site you have a blocker enabled and the site would refuse to load.