How independant from servers is Graysky?

[ProgrammerWhoPrograms]

I.e.

Clients can rely on network services (eg, their PDS) to resolve handles for them, using the com.atproto.identity.resolveHandle endpoint, and don't usually need to implement resolution directly themselves

https://atproto.com/specs/handle

Which one does Graysky do?

2. Does it support third-party and self-hosted PDSs, relays, and app views?

3. Does it certify the "self-certifying data"?

4. Is it possible to use a self-hosted did:web instead of the completely centralised did:plc?

That kind of thing.