Technically, all interesting. Ethically, if you don't only think “fuck Google”, I feel like it's reasonable to stop after the first optimization (“pass the real browser test to get regular browser speeds”). There you're not “wasting” any more of YouTube's resources than a browser user with ad-block. Getting full Gb/s without paying anything feels to me like you're pushing all the ad-blocked users' luck. But then agai…
Technically, everyone pays for connecting to the network. I wouldn't say it's unethical to slam YouTube with full speed downloads but at the same time I wouldn't judge YouTube if they take measures against it. I'm using a browser extension to show full size of images on social media when hover and Instagram went crazy about it, warning about unusual activities and threatening to lock my account. I looked into it to s…
I've used such an extension and found dragging the curser over your screen might fire like 25 requests. You might simply be rate-limited.