Atmosphere mass fraction and core mass for four planets as a function of time. The atmosphere masses remains low during pebble accretion due to the high accretion luminosity. Once pebble accretion is halted after pebble isolation mass is reached (triangles), the gas rapidly contracts due to the high initial luminosity. With the exception of the planet injected at 20 AU (dash-dotted line), all planets reach the inner edge (crosses), where gas accretion is halted, before a massive atmosphere has been accreted.