From what I'm aware of 12 car triple 360s will only run during the peak and shoulder peak periods of the day in both peak and contra-peak directions, but at swt_passenger says there will be technically enough 360s to run 12 car formations all day if needed. Off peak is a mix of 4 car single and 8 car paires of 360s, with a 5 car 222 working a Corby extension to and from Melton Mowbray, for their 2nd daily London service (slightly off topic I know).Somewhere I've seen that the plan is to run the 360s in 12 car sets all day. Can anyone confirm this? And also, how many seats (after fitting 2+2 and 2+1 seats) will there be in a 12-car?
As for seating after they've been refurbished, again I'd go with what swt_passenger has said in that it would likely be something similar to the TPE 350/4 layout. Hopefully it's not long till we see something official about this.