I don't see a point in mapping a game unless I have (at least) a Freemove code. I usually have to find them myself.
I see no point if you can't be sure you captured the entire map.
I used three codes:
0300640B 0000   No Random Battles
03006415 0000   Timer for background animations.
0300643c 001E   Increases movement speed and allows walking through objects. Transitions still work.
Here are other offsets:
There are three spots for camera coordinates. Each one belongs to a layer (BG0, BG1, et cetera). I just used this one.
0300057C   Camera X-coordinate.
0300057E   Camera Y-coordinate.
03005312   Setting this to 03 will reload the map. Setting it to 01 will move you in the direction you are facing, bypassing objects.
03005FDE   Map ID
03006432   Actor X-coordinate
03006434   Actor Y-coordinate
The actor location, camera location, and map ID were used in my mapper program. Finding the byte that reloads the map is what made this fast. Here was the process. I was using write mode on my mapper program.
0. Set map ID to 00.
1. Reload map (change byte to 03). This loads the map corresponding to the current map id.
2. Capture map.
3. Hit Save button.
4. Increment map ID.
5. Back to step 1.
Because the maps were small (all smaller than 512x512), they took maybe 15 seconds each to capture. It was pretty ridiculous, to be quite honest.