I just double checked. She technically disappears between the episodes An Obol for Charon and Saints of Imperfection, but the scene from Obol she's in is directly continued in Saints with no time skip at all. Basically, if you take the scenes in engineering from those two episodes and watch them in real-time, Reno would simply vanish when cutting from one camera angle to another.
Really? I thought Stamets was the worst character. It like they sat down and said "ok, we need a character that's gay and neurotic" and then stopped writing and didn't flesh him out at all
Stamets grew on me over time. I don't know why. Possibly because he was often the only competent character on the ship. As neurotic as he can be, he's still less neurotic than season 1 Saru and has better decision making ability than Burnham.