JADE simulations of atmospheric evolution for TOI-3862 b. Left: posterior distribution of the initial planet mass. The median is marked by a blue line; the 1σ HDI is shown as dashed green lines. Right: temporal evolution of the planet’s radius in the best-fit simulation (blue) and a representative set within the 1σ HDI (green). The red point indicates the measured age and radius, with associated uncertainties. An inset shows a zoomed-in view of the planet radius over a narrower range.