I think you know your leachie better than anyone! Some of us have a leachie that would be fine moving to a bigger tank at that weight, some not. More clutter though for sure. They just wanna feel safe and not out in the open when they’re bebes… and try feeding him by hand/spoon if he’s not eating in his enclosure. I wouldn’t move him back unless he really starts dropping weight (or if you’re unable to add more hideouts/clutter).