If you didn't know - the new officer entering the bridge taking over Airiam's position is played by the original Season 1 actress who played Airiam. I am not exactly sure why she stopped playing Airiam, one rumor I heard was that she had allergy problems with the make-up. (Farscape and Andromeda fans might remember other actors having problem with their and having to lower their involvement in the series.)
I actually liked the techno-babble this episode, it seemed to actually make sense within the context of the show. A Time Crystal was also used by Harry Mudd in his Season 1 episode. They are a real thing, but despite the name don't really have anything to do with time travel, but represent a system undergoing a periodic, self-repeating cycle.
Despite that, one thing was missing - the never really explicitly said that if this if the Red Angel is really future Burnham, she'd know of the plan and could prepare herself for it. Now, of course the Red Angel has no choice but to save herself (if you can guarantee that no one can save her but the Red Angel, which only Spock fully acknowledged - but the rest seemed less understanding of that?), but one has to wonder if she can't prepare some counter-measures. So if she falls into the trap, then either because she has limitations that they can't beat, or she needs to want to be captured. If the latter was the case, she could have that easier.
Of course, since the Red Angel turns out to be Burnhams mother, not Burnham herself, she cannot necessarily anticipate counters, but the Disco team had no way of knowing.
That the Red Angel doesn't turn out to be Burnham after all, makes one wonder: Did Culber win his Doctor-grade in the lottery?
Of course, there are alternate explanations: 1) The Red Angel will become Burnham. 2) The signature they found isn't really from the Red Angel, and instead was placed by someone for other reasons. It could have been a trap, or it could have been that they found out the Red Angel was looking for that signature. Maybe Burnhams mother was "stuck" in the suite and only went around saving Burnham, and the Red Burst stuff happens when Burnham takes over the suite, for example.
I don't like the idea of Section 31 developing its own time travel tech, but on the other hand, time travel tech in Star Trek is not that hard - Kirk is after all uses it as well. Interestingly at least, the Section 31 tech seems to require a rare material (Time Crystals), so that limits the availability of the tech far more than just warping around the sun.
Star Trek Online Advancement: You start with lowbie gear, you end with Lobi gear.