This is a fairly minor one, and I tried to read through here to make sure nobody already mentioned it, but my dyslexia could have caused me to miss if someone did mention it. I apologize in advance, and I fully understand if you want to just delete my post.
Anyway, there are some segments where a character approaches you to initiate dialogue outside of a cutscene, such as on a large street toward the end (trying to not spoil stuff), where you can hold down or mash a movement key to continue walking; I was able to lead a certain someone to the location of an actual cutscene, where he appeared to duplicate himself for said cutscene, since he has dialogue in it. I am aware of the possibility that this could be an engine issue itself, and not something a game developer can fix. Since I have never used this engine in my life (the only version I used was XP), I have no way of confidently saying whether I believe this to be an engine issue or not, but based on my experiences with other engines, I can certainly see it being a possibility.
Viewing post in Bug Reports Thread - Version (0.5.1 to 0.6.2 (Content Pack 1))
Spoilers are fine here: The assumption is that bug report sections are going to be spoiler central regardless, because they kind of have to be to clearly discuss issues. Appreciate the thought though, and definitely keep to it outside these threads.
So I assume you're talking about the little walkup and talk Mahir does when you get to Entertainment District II? In theory you're supposed to be stopped there yes, and in my testing it didn't seem possible to move. However, when I was first programming GT, I ended up using a fairly hacky solution for this: I have some dialog before he comes up, then trigger him to come up, and on touch the rest of the dialog happens. At various points during this player movement is frozen, but not ALL, so I tried to get around it by having a 1 second wait, which USUALLY was enough to patch over that gap, but it's really inconsistent. Since then, I've discovered the RIGHT way of doing it: just completely and directly disabling player movement, then turning it back on after. I avoided going back and fixing all the old ones, as they seemed to work well enough, but I'll adjust this one since you were able to get past it. Appreciate the report.
If spoilers are alright here, then I also was able to do this with the door greeter in the host club (the mouse), although it is a lot more difficult to pull off due to him being right next to Mezz when first entering. On that note, I was able to get to the intended guest and initiate the game with him without wearing the costume, and after beating him, the mouse seemingly goes back to his original position and everything proceeds fine as if this segment was done legitimately. So while it is obviously unintended, it does not seem to be game-breaking for this particular part of the game.