As someone who runs an EA chapter if I get messages from people reasonably often. In the past I have offered to meet people to talk about EA stuff one-on-one and have had this offer taken up. I no longer make this offer due to lack of time. But having someone (ideally someone local) who could meet people could help outreach in London.
This is what I’ve been setting up for the new local presences I’ve been creating, and for existing EA groups. I’ll put contact details for these local people up on the list and map of EA groups soon.