I appreciate that you’ve put a lot of work into this project … but I still don’t understand what problem it solves for?
You’ve “nostrfied” the legacy ad model, allowing transactions to be more transparent. This does not ad any value for the end user or for the other two parties involved. You have not put the end user in control, and there is no incentive for apps or advertisers to change from their old ways … aside from the purple washing of ads now being “nostrfied”.
“Trustlesness” is simply a milestone for measuring the value-add for end users. If a solution does not aim for “trustlesness”, end users will be required to “trust” that the app developers are respecting their sovereignty. In a free market of apps, this “trustfullness” is buffered a bit, but also requires that a healthy market of multiple valid choices exists for the end user to choose from. That’s fine if you assume this.
I come from the mindset that transactions involving money should be trustless, but that’s just me.
The most important oversight in your solution here is that the end user doesn’t get control over or value from this “ad placement” transaction. The “Nostr way”, much more than a technical solution, is one that put users first. This is what I would like to see.