Not sure if I understood you correctly, but here is what I meant as follows.
I meant "DataB1", the Maximum Total Damage, which is capped at 99999. I tried to set it to 0, then it really has no damage. I tried Breath of Fire for example. My understanding is that such spells don't limit the number of targets but the total damage all targets receive is capped at 99999?
I tried to open it with "shift" held and set it to a higher number, but it doesn't seem to work.
For Thunder Clap there isn't even this field "Maximum Total Damage". There is only "AOE Damage" which is per target, and the total damage is uncapped.