Let's Share our mod experience here for more specific....
I have been using mods since about my level was 50, but the mod was only for attack and defense, and then my friend use the same mods too. we enter FH together, using mods, mine was about lv 80, he was about 50. even though we using the same mods and my FH score is still far higher than him, he got banned, my other friend also got banned when i am not... so, when we discuss it here, let's specify our level when modding also.... here is my experience:
About lv 80: 3k atk + def (only)
from lv 110 - 150: 0 energy, vortex, instant win, evo, no key, 200 unit capacity, 200 item capacity
I haven't played BF for about 6 month, and then played it again since last week, i used this mod, i level it about 10 levels a day and still not get banned, i use vortex mod, still not get banned even though i clear every vortex that already closed(for gems, sphere, and other things). i use 2 gems for unit capacity, so my unit capacity now is 500++ and item capacity 300.
I think the higher the level, the lower the risk for mod....