Modelled optimal tidal heating zones (green shaded regions) and tidal stress threshold (red dashed lines) against the CHZ (blue shaded regions), adjusting for parameters of planetary radius, eccentricity, semi-major axis, and stellar mass. Light purple regions represent the area of overlap between tidal heating zones and the CHZ. Dark purple shaded regions represent the area of overlap between tidal stress, tidal heating, and the CHZ. Black dashed lines represent the tidal locking radius from Barnes (2017) Constant-Time-Lag model.