A temporal URL here uses different random looking values for the each user rather than a fixed one (like a URL shorter), and encode a validity window (not before/after).
The core idea here being that the code in the app doesn’t know the difference between ads and user content, which would make it very difficult for any intermediary to do so. And, if if they did the URL for the “real” content wouldn’t work until the time to play the ad had passed - so what’d be the point in bothering?
Like others have said - ya just have to pay for the things you value. No shame in being thrifty, but as I learned from my first employer: pick great suppliers and never force them out of business.
I really hope that that would be enough to finally coax the antitrust regulators into doing something.
TBH baking it into the video stream is probably the easiest path. The whole video doesn't have to be re-encoded if the ad is spliced in. This is a "soft lockdown" since the ad can theoretically be manually skipped by the user, but its probably good enough.