Snapshots of the T–P profile (left)for a series of test models investigating the effect of deep radiative forcing, via deep isothermal Newtonian cooling, on already evolved (dark grey) models of both Kepler-13Ab (top) and KELT-1b (bottom) with a deeper horizontal convergence pressure. For each brown dwarf, we explored models with increasingly weak deep forcing, as shown by the matching profile on the right, where the full Newtonian cooling timescale profile is found by combining the dark grey profile at lower pressures and the matching coloured profile at higher pressures.