you can extend the battle size in the python editor system by changing the values in the modules_scense.py
("random_scene_steppe",sf_generate|sf_randomize|sf_auto_entry_points,"none", "none", (0,0),(240,240),-0.5,"0x0000000229602800000691a400003efe00004b34000059be",
[],[], "outer_terrain_steppe"),
which is the maximum range of movement before the 'leave battle' option kicks in.
in the mod text file, scenes.txt the number to change is found here:
scn_random_scene_steppe random_scene_steppe 1792 none none 0.000000 0.000000 240.000000 240.000000 -0.500000 0x0000000229602800000691a400003efe00004b34000059be
0
0
i think i remember finding out that the terrain generator in game designates the size of the battle field, and gives you a x/y limit. i think i got up to 999/999 before i had problems - dunno if it was game engine, graphics card, or my cpu that limited it.
luck. maw