the observer pubkey is your pubkey.
would you just do a chickensoup set of tags maybe? if so, then streaming from a large relay that supports streams is a good way to easily populate the relay with notes that match both the web of access+keyword or kind.
you could try streaming from .. say primal, or maybe damus to start. or try a stream from primus (a combo of those, but filtered by *my wot observer already). many possibilities. some relays do not support the stream, but many do. i can let you know if a stream is not working, so far i have not bubbled this up into the UI yet.