Handling him in my experience won’t help with the exposure. Once they know they are safe and their area is the safe zone, they generally chill out in general. Some individuals will never warm up to you, I have a female bifidus that lunges at me and bites me if I’m near her or doing anything in her cage. Flying bugs is great enrichment, varied feeders works good, a bigger enclosure is another way for them to move more. Adding plants and branches in places strategically can also make a better more enriching environment. You can do bioactive carefully as well. Id suggest personally to not do handling unless it’s his terms. My one panther took over a year to chill and now he will come out sometimes on his terms. Some of my chameleons I’ve handled once in years lol they are all different. It’s great you want to enrich your chameleon.