As part of the preparation for the second JET DT campaign (DTE2), a series of isotope control experiments in H/D mixtures [1] have shown that NBI fuelling species has only a weak effect on the core isotope composition, which remains determined by the edge H/D ratio and therefore by the injected gas. The analysis of the core particle transport of the ion components revealed a fast isotope mixing ubiquitous in plasmas with dominant ITG turbulence [2-4]. Fast isotope mixing offers an opportunity to significantly boost the fusion power in DTE2 in a variant of a hybrid scenario [5,6] with unbalanced (tritium rich) D/T isotope composition and pure D-NBI heating, as opposed to the symmetric 50/50 D/T mixture and combined D- and T-NBI. Thermonuclear fusion reactivity (reactions between thermal fuel components) reduces as the plasma composition deviates from the balanced 50/50, although injection of fast deuterium into thermal tritium plasma greatly enhances the beam-target fusion, due to the large cross-section of D_fast->T reactions and increased number of the tritium targets. In the parameters space of JET hybrid scenarios that gives a net increase of the total number of fusion reactions, with larger gain at higher tritium concentrations. Further to the NBI fast-thermal reactions, the low expected D/T ratio (n_D/n_e ≤35%) enables the usage of deuterium fundamental harmonic ICRH heating scheme which further boosts the fusion power, as, unlike in 2^nd harmonic schemes, it avoids accelerating fuel ions to energies well above the peak of the DT cross section (~120keV). The fundamental D minority heating demonstrated the highest Q_fus=0.22 in DTE1 (1997) for a 4 second stationary state plasma [7]. In the proposed scenario, part of the ICRH power will also be absorbed by Doppler shifted D-NB ions and the intrinsic Be impurity as the resonant species in a three-ion heating scheme [8]. TOMCAT and TORIC simulations have shown that the fractions of the total ICRH power absorbed by the individual components depend on the exact plasma D/T composition, with more power going to the thermal and fast deuterium in more T-rich plasmas. Therefore, larger D/T imbalance also provides larger boost to the fusion reactivity from the ICRH heating. Combination of the NBI beam-target reactions with the ICRH effects in the proposed scenario has the potential of boosting the fusion power significantly over an otherwise similar hybrid plasma with n_D=n_T, bringing substantial benefits to the physics goals of DTE2, such as the investigation of alpha particle physics.