None of them for the first timeline, I believe. I mean, there's like 3 or 4 "reminders" encouraging Euca to actually make that decision in time, so darkest history doesn't repeat itself. And after first one, time loop makes all routes canon.
Honestly this also makes sense for not imposing a "true timeline" for the story and the fact Echo forces the doors shut on Euca's "first" day, I would like to counter this and say that some text implies that Euca is just avoiding being alone with his thought and would be more active than that.
But overall we gotta wait and seen considering Shirokoi is like what? 1/5 of the way done? more or less depending on what he's cooking hopefully if we get another big update it adds more fuel to this fire.
With the flower how they talk about the "forget me not" we can every well assume that one is Euca the player character and the flower say before the "forget me not" can be saved the others must be helped so yeah I'm sure that will possibly be an ending or the saving of Jinny either one makes sense for a conclusion.