Robo-Sara didn't even know that Thawne was in this point in the time-line, but she and Robo-Nate found him very quickly.
Behrad tells that only one blind spot on Waverider is toilet, but it was Bishop's change. Original Waverider had a camera inside toilet, so there is no way Behrad could learn about Bishop's changes to Waverider construction.
When real Zari goes to shutdown Evil Gideon, she searches for the letter Delta on the keyboard because that was a part of the override code. When there is no Delta key on a normal keyboard, how can someone put a password having Delta in override code? Of course, there are ASCII code sequences that could enter 128 more letters, but an override is needed mostly on very crucial juncture, and at that time, not being able to remember the ASCII code entry method or not able to remember the correct code would cause delay of precious time that could be fatal.
When Gary should have been keeping a watch on the portal's door to see Android Zari stepping in at any moment, at that very crucial juncture, he leaves his post and goes to chat with Astra about mama bear protecting Gideon. That was so undisciplined and shabby that all the Legends always are. It almost cost the real Zari her life. Poor scripting.