Quick update this morning. For the third day now, the change in height has been at one inch daily. I am still expecting it to open any day now. I will be back in the greenhouse between noon and 3 p.m. today to see if it decides to open today.
It's 3 p.m. and the spathe has not budged at all, so it's not going to open today. Will have to wait until this time tomorrow (Sunday 9/11) to see if it decides to open. As always, you can see what is going on with Titan #2 via the live stream.