OK, I'll try to upload a couple of photos of the venue via twitter.
I arrived on the crowded Yurikamome line train at Aomi before the 10:30am opening and joined the queue, not knowing how long it was. A while after Venus Fort opening were were lead through to queue for CD's/vinyl and I noticed ZP a few rows back.
After purchasing one of each of the CD's as the vinyl was too big to carry easily I waited for ZP and then went to find the mobile charging station which was near the information desk at Venus fort (100 yen for half an hour). Our tickets that came with the purchases listed a time for queuing of 13:00 which turned out to be in a stairwell near the entrance. Mine was 114, ZP and his family had tickets about 256, the numbers weren't really random like the staff blog claimed.
So we were lead from the stairwell back to the church plaza and at 1:30 the Kalafina girls appeared for the "open rehearsal", singing bits of Hyakka Ryouran and Symphonia and talking to the audience and staff until 1:50pm when they left.
At 2pm they appeared, and sang Hyakka Ryouran with the Hikaru - Keiko dance that they had rehearsed, then introduced themselves in Wakana - Keiko - Hikaru order. They then sang Tombo and Symphonia. I found the acoustics of the venue a bit echoey to fully enjoy it but the girls seemed reasonably comfortable with it. Then it was photo time with a large number of photographers mainly taking photos from the back of the stage facing the Kalafina girls with the audience behind them.
After the photos had been taken at the end while the Kalafina girls were waving to the audience I held up the poster that my Japanese friend had held up at the end of the Believe Mini Live from Kawasaki in 2014:
https://lineblog.me/kalafina/archives/42370281.html (on left) and the Kalafina girls all noticed it and waved back, and finished saying their goodbyes to the audience and left.
After that we stayed queued up for the posters and those who had more than one purchase earlier were able to get extra posters, so I have 4 posters and 2 are up for good homes.