It's hard to strike a balance between chaos and routine. You want enough routine that players can explore the game and find their comfy, but you want enough chaos that the routine becomes disrupted and your comfy must be protected.
If I had the means to remake the game I would set on rounds being an hour long and it would take about 30 minutes for shit to hit the fan. You have a warmup period where people can prepare, a build up where minor roundstart antagonists start to cause problems and people have to do more than just focus on themselves, and then a climax towards the end where the station is basically guaranteed to die. Station explodes, music starts playing, everyone spergs in chat. Rinse and repeat in 3 minutes.
Current SS13 doesn't really do that. It accidentally achieves this on a good day with the right players. With the wrong factors it's a 4 hour long slog where engineering is setting up 3 engines and the rest of the station is afk. Or it's a 20 minute shitfest where nobody gets to achieve comfy and therefore they're just annoyed with the incompetence of other players.