Comskip has a pretty wide array of detection. They also look at percent scene change,volume , closed captioning, aspect ratios and duration patterns. The sweet part about the duration patterns is we know the contents supposed length. You could analyze the piece of media figure out how long it would be without it and look around for other options that are less obvious but make the right time code.

I've been using comskip for years, I suspect if it ends up being the tool we need will have an arsenal of people working on it to tune it for whatever YouTube's doing.

They're just looking to knock out the easy methods, they're not going to try to wage a full-on ground war. Their primary goals are probably to stop ublock and brave, and keep YT-DLP from downloading without ads. secondary goals being to stop or slow down revanced, though I think Google's going to try to do that for them in security.

I think the next logical step if they can't block us with reasonable means would be to do some custom encryption in the app. Again not insurmountable but hard to crack out right.

I think using a server to download the whole steam with ads then remove the ads, compress and store the files is really the hardest thing for them to stop.