Yes the seating is Aer Lingus high density, the pilot and first officer are definately EI as they all spoke with Irish accents. I’m not sure about the cabin crew, they may be employed by EI but none of them on my flights were Irish.
The reason I knew there was only one tranfer is because when the flight was called they asked for connecting passengers first and preimium card holders. I might be wrong but as there was only one I assumed that the guy that went forward was transfering as I noted an upper class lable on his hand luggage.
I have been on BA flights around this time and they have been full or only a few seats available. I can’t see that this is worth while for Virgin