welcome!
The fact that after one day he's preening away and playing in your presence is great!
Unfortunately even being hand-fed (most breeders saying hand-raised often mean hand-fed. I'll explain the difference further down) so he will be more open to hands but still he has been abducted from the world he knew and his family and is suddenly alone with you pushing hands at him. It's nothing personal, he's just upset and scared in a new home and isn't sure what's happening yet, he just needs some time to settle in. As for getting comfortable and settling that is up to him, all you can do is keep things calm around him and make every time you interact with him positive, try holding a treat through the bars and see if he comes over, if he doesn't come over and looks calm drop the treat in his food bowl and as time goes on he should figure out that when you're around a treat appears! As time goes on he should notice the treat in your hand and start coming over, if he doesn't want to come to you don't force him to, let him decide when the time is right to interact, you'd be surprised how fast they can turn from not wanting to be with you to being nestled on your should ready to sleep!
So I personally say there are 2 things breeders do. The majority hand-feed, what this is is where they feed the babies by spoon or syringe until they wean then they sell them off. Hand-raising a bird is where the breeder hand-feeds the chicks but they also handle and play with them daily to get them used to and happy with being touched and held by humans. I'm trying to push for people to start using the 2 separate terms because I feel it's important and should be a good way to stop less reputable people selling babies off for the same cost if not more than people who put in more work