I can change festival lots though I need to activate cheats first and make sure things get added to the right modes.I just start my scratch builds like any other normal builds and set spaces aside for seasonal items to be placed in each season's mode.You don't have to keep the festival lots as they are if you follow the right steps in editing it.I would activate TCE and buy debug cheats before changing one of the EA lots and switch the marker to the right modes with it being switched to common mode in between each mode switch.