Before COVID, EVA had three SFO-TPE flights a day. One left around 1pm. Two left past midnight. Many US-TPE flights arrive in TPE at 4:30am-6am. It is good for making connection to Southeastern Asia and even to Japan/China.

As for confusion to have two EVA aircrafts boarding next to each other sometimes, I am not sure why it is a problem. Isn't passenger's responsibility to find out the correct gate? Go to G gates in SFO to see how many United flights leaving from there?

BR7 can't be booked on April 9. Perhaps EVA does not see the strong demands back for daytime flight before summer. This week is CNY holiday. I would wait until next week. EVA should send a flight schedule change email if there is a cancellation.