I had to ask Sled One (who happened to be painting further along the wall) who this piece was by, because I didn’t recognise the style when I first saw it. He told me it was by Joe Poe or Poer who is from London. This would explain why I am not familiar with it.
This really is a top drawer piece of wildstyle writing from a classy artist who I really know little about. He seems to be a member of ASK or possibnly just received an invite to paint with them. I’ll have to do some more digging.