Re gaming the system you're totally right. Although slightly unintuitive, we've also heard the opposite from maintainers. That they'll be motivated to remove the silly one line packages from their dependency trees due to the imbalance of value they provide vs extract.
We also prune self dependencies, circular dependencies and a few other cases to keep things level. Hopefully we'll be at a stage to open source our codebase soon and can better leverage community feedback in this space :)
You're absolutely right. When you login you can actually see a list of dependencies & make your own adjustments. While thanks.dev makes a recommendation based on what's analysed, sponsors are able to boost or exclude beyond our recommendations. It's not perfect & has a lot of room to improve but we hope it's a good starting point :)
If this takes off people will be inventivized to make lots of small dependencies that are likely to be needed in tier 1 (or tier 2).
The trick will be to find a bug in a first dep of webpack for example, fork it and fix some bugs there then convince webpack to switch to you.
Algorithmic decisions can be gamed.
I suggest instead the app lists the deps, and you choose how much to give each one.