Baby beardie scared to have glass uncovered

So my beardie is almost 3 months old now, ive had him for just over 2 weeks. The first week he wasnt doing well, not eating, not basking. Now he's doing great, eating like a champ, soaking up the sunshine, and growing already.

What made a difference was I noticed he would run into a hide whenever i came into the room and only look for food when I was out so i covered the front glass part of his viv with cardboard so he is completely secure. It worked great.

But I want to see my beardie. He runs into a hide whenever i remove the cardboard and won't come out until i put it back. Stress marks appear if i leave it off too long.
Im trying to transition him, leaving it off half the day and on the other half. But he wont eat or bask with it uncovered.

Any ideas how to get him used to the glass being uncovered? For what its worth he's fine being handled, but ive only taken him out a couple times and only for a few minutes.

Maybe try offering him a treat by hand. A black soldier fly larva or small silk worm perhaps. That might help build some trust and get him more used to you being around his tank.

I think is a question of time and habit, i remember that when mine were little, everything was difficolt, they were scaried by everything.
Now they eat new food just if i offer it by my hands first and when they are free, if they dont hide to sleep they come near or over (up?) me.

The trick is to give him succulent food with your hands, bribe him, even if some breeders are against it.

Just get him used to you. Bribe him with insects, hold him, and generally show that you mean him no harm.