I totally forgot about that scene where it does scroll. If worst comes to worst I could probably just have it forcefully close the dialogue box so there's no worry on that. I don't think I could properly implement it scrolling with the screen as I still don't have a good handle on HDMA and everything else quite yet. Just allowing better tiles is a huge step forward for this.
Edit: Okay now that I'm actually thinking about it with some time I have spare today, how would one go about figuring out a way to determine 'where' you the character is currently according to VRAM with BG 1/2 and such? I'm sure it's different for each game and my best guess to go off of would be Final Fantasy 6 since both of these games use tile movement and share a very similar system.
Edit 2: Was studying Chrono Trigger's system a bit still. I'm actually really confused by it still. The Tilemap address does, indeed, change for BG1 and 3.. but the BG1 address is changed to where BG3's is, so they share the same area oddly enough. But even then, it STILL uses the original Tilemap location to draw the BG1 tiles! As far as I can see it looks like it's using HDMA basically as a way to draw the rest of the tiles but that seems.. odd. If I could replicate what they did I could probably make it work but they do some crazy stuff with that game, most notably setting the Y coordinates to way in the 8000 which sets Vector D in Mode 7 to be 256 and it's coordinates to be 8000+ as well... blegh.
I'm trying to figure out an approach to BOFII that I can use but I'm coming up empty handed. With how the game draws tiles originally, even adding in a separate routine to draw the remainder of Layer 1 will still overwrite everything so I can't simply just change the tilemap to be 256x256 instead of 512x256 without some extreme rewriting of every tile map in the game. Minus that, I cannot figure out a proper method to get the location in VRAM to write to depending on the players coordinates or even the cameras. There's so many variables that it's making it nigh impossible to do. It's doable just.. I'm not sure what will work.