<p>We propose the physics of symmetry-selective resonance of the Δ₁ states in the Fe/ MgO/ ZnO/ MgO/ Fe heterostructures, offering a broad landscape to design high-performance magnetic tunnel junctions (MTJs) via first-principles calculations. These MTJs yield a towering tunnel magnetoresistance (TMR) up to 3.5 × 10⁴% with the resistance area (RA) product dipping down till a minimum of 0.05 Ω.μm², while maintaining a nearly perfect (99%) spin polarization. Our predictions are based on the self-consistent coupling of the non-equilibrium Green’s function(NEGF) with the density functional theory(DFT). We also present the charge current, spin current and TMR of a prototype(p) Fe/MgO(3-layer(l))/ZnO(3l)/MgO(3l)/Fe-MTJ(abbreviated as p-<InlineEquation ID="IEq1"><EquationSource Format="TEX">\({\Delta }_{1}^{R}\)</EquationSource><EquationSource Format="MATHML"><math><msubsup><mrow><mi mathvariant="normal">Δ</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>R</mi></mrow></msubsup></math></EquationSource></InlineEquation>-MTJ), which exhibits a pronounced improvement in the TMR (1.3 × 10⁴%) and a significant reduction in the RA product (0.45 Ω.μm²) over its Fe/MgO(6l)/Fe-based regular (r) counterpart (TMR ≈ 3.4 × 10³%, RA product ≈ 23 Ω.μ m²) with a comparable spin polarisation (≈99%), indicating a notable improvement in spin-transfer torque(STT). We substantiate our findings by combining the transmission eigenchannel analysis, spectral density, and Fe-contact band structure in the p-<InlineEquation ID="IEq2"><EquationSource Format="TEX">\({\Delta }_{1}^{R}\)</EquationSource><EquationSource Format="MATHML"><math><msubsup><mrow><mi mathvariant="normal">Δ</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>R</mi></mrow></msubsup></math></EquationSource></InlineEquation>-MTJ, thereby elucidating the physics of symmetry-selective resonances.</p>