You can use MasterVolume to go above 100%
https://github.com/averne/MasterVolume
I am using 300% and in V2 it works fine as long as you have system volume set to max.
I tried both E-108 and MaAnt D1/D2, both of them works good, but I prefer MaAnt as the vibration is lesser than the E-108. For kamikaze, you should be using a 0.2mm tip.