Since the p2p network relies on people hosting and seeding I do see how a "boolean flag" for checking if the visitor is "hosting" would be a nice thing to have for some hyperdrive owners have put a lot of effort in gathering and publishing their content on the network.
And therefore I could understand that this could be used as a form of "paywall" to control the access to "freemium" content. I think this would be only fair if used in moderation. To call it "extortion", is a bit exaggerated as the whole network literally depends on us sharing each others content.
However, there are indeed privacy related issues. This API, together with our public IP addresses could be used to create a way for some hyperdrive owners to start tracking their visitors.
If the "gratitude" feature would be part of the main Beaker interface, within Sharing Hyperdrives, I will leave open here.
Perhaps it should be made "optional" for the visitors, within the permissions dialog, to disclose to the owner of the hyperdrives to announce that they are hosting the drive or not. Beaker browser itself should not show any explicit banners or notifications. That would be up for the hyperdrive owners to interpret.
Technically, I would even add a datetime stamp so there are more variants possible in how the hyperdrive owner can process is visitors are seeding or not.