I'm getting a little anxious that only the Christ Cathedral concert has tickets available so far. I would hate to see meager attendance for the other concerts due to the short time frame for selling tickets. If I recall correctly, the 2015 concert at the Tobin Center was pretty well attended, but the concert announcement and ticket sales were more ahead of time compared to this year. I hope that some Libera fans will do what they can to spread the word about the concerts.
In terms of seating capacity, the Cathedral of Our Lady of the Angels in L.A. is the largest, with a fixed-seating capacity of 3000, and room for up to 1100 more people. I'm not crazy about the cathedral's architecture, but the acoustics are supposed to be pretty good. Here's a pdf link that talks about its acoustics starting on page 5:
http://www.acsforum.org/symposium2011/p ... oletti.pdf.
I'm not sure what the seating capacity is at St. Ignatius in San Francisco, but I'm betting it's over 1000. So far, St. Ignatius is the only other venue besides Christ Cathedral that mentions the concert on their website/social media. St. Andrew's UMC in Plano has a seating capacity of either 1649 or 1500, depending on which website you look at. It seems to have some technological features that are similar to Asbury UMC in Tulsa, where Libera performed in 2017.