One thing I want to point out about https://pubkit.net is that I know a service like this could be easily abused!
This is why you will have to verify ownership of servers you want to test against
It can be a text file or DNS record, and in special cases, I can make exceptions for devs who want to test against instances they can't publicly verify
The point is, PubKit will be opt-in, and won't require a fediblock, services like these can be done right 😎
I had an interesting idea for PubKit, I do want to open source the code but I'd also like to get some funding/donations while keeping the service free.
The idea is to set a goal, say $15,000 of donations to reach before the source code is published, basically incentivizing the release by a set monetary goal.
https://pubkit.net will use client side encryption (NaCL) when storing fetched ActivityPub objects, and the user will have the decryption key added to a link they can easily share.
Privacy is important, and this enforces it in a clever and easy way!
The activities are encrypted at rest and decrypted on the web using a key in a hash fragment (never sent to server)