During the MKII Divertor campaign the performance characteristics of the Hot-Ion ELM-free H-mode regime in Deuterium plasmas have been comprehensively explored [1,2]. Experiments were carried out up to a plasma current of 4.2 MA and a toroidal field of 3.8 T, with Neutral Beam (NB) heating alone and with NB plus Hydrogen minority Ion Cyclotron Resonance Heating (ICRH), up to a total input power of about 25 MW. The maximum fusion reactivity is obtained transiently; density and stored energy rise continuously with time, until the terminating MHD event, which is either a large sawtooth, a Giant ELM or an external kink mode. The identification of the so-called Outer Mode as an ideal external kink, driven by the edge current gradient, led to the development of a method for its mitigation or avoidance by decreasing the plasma current during the ELM-free phase. As a result the performance, robustness and reliability of the regime have been improved, extending the maximum DD neutron yield to 5.2¥1016 s-1 at 3.8 MA/3.4 T with combined NB+ICRH, thereby making the regime an ideal candidate for high performance experiments in DT.