I think the arena settings were inherited from The Hardest Day that was played August 19th. There, the icons where set to 6k above a certain altitude and 3k (half) below.
This should not be the case. FSO is in SEA 1, whilst Scenarios are in SEA2.
There must also be a flyable computer available for Nefarious to do FSO. So he doesn't keep talking about it for eight and a half hours on Friday night!
I know for a fact the claims are correct because we did not see those P-40's until 1.5k.