Lina wrote:

1.exp gain from burst is depending in damage.
2.without hf, damage gap is over too much it can count as fail burst (i think)
3.other element even cant attack but still can assist burst that giving much more
exp than who attack.
4.fire element correction almost highest for every element target (for burst 1.3).

i can understand, the rest i don't really understand

3.other element even cant attack but still can assist burst that giving much more
exp than who attack.
I said this is a theory but maybe if water,earth,wind has successfully used there 3rd round support skill i believe they can attack