hello man , so the short answer is no it needs the unity tool so you can customize the characters and save them as prefabs .
the long answer is all the clothing and models are included as fbx files , so you can customize them "manually" in godot as well .
im currently busy with my game it migth take me another month at least but after that im planning to drop a new update 1.4 for my tool that includes godot as support as well as well as new models and customizables , hope the answer helps :) .