PSA: Don't send your PMs to Scott Pilgrim, send them to scott_pilgrim. That's what happened to me in round 2.
I had intended to build tower B in round 2. Had that worked out, I would have built F1 in round 3. Then since faust and I both played A in round 1 and G1 in round 4, we actually made the same decisions every single round, which is neat.
It was pretty unlucky that in round 3 three different people did three different things (D,F1,G1). I thought F1 was best because we could clearly complete A,B, and F1 with some wiggle-room to spare. I can understand choosing G1 but F1 should have been achievable. Tower D just seems strictly worse? After round 3 though it was doubtful that F1 could happen so I went for G1, since I was confident that B would complete.