Excitation coefficients of HCN, HCO⁺, and HNC in DSFGs from our sample (coloured), normalised to the (1−0) transition and compared to z ∼ 0 galaxies from the Israel (2023) compilation (grey). The arrows indicate the 3σ upper/lower limits. For comparison, we highlight SLEDs for nearby (U)LIRGs NGC 253, NGC 1068, and NGC 6946. In J0209 and J1202, the HCN and HCO⁺ SLEDs appear to be superthermalised. The sparseness of the HNC plot reflects the lack of detections at z ≈ 0.