I think it can't hurt to have a thread used for general questions.

Right now, after going through the (Demonic) Whirlpool Dungeon, I stumbled into Future Riftonia, and on the way there, one of the dialogue panels showed someone who hasn't joined my party yet, so I'm cutting my losses now and returning to a previous save file. If this location shouldn't be accessible right now, it would be better to prevent the player from entering it at this point; otherwise, it would at least be great to know if there's a way back from Future Riftonia. I'm a player that always does main quest related stuff last, but I don't want to waste my time with sequence-breaking. It's hard to figure out if something breaks the sequence with all the time-related shenanigans going on. :P