If he has a lot of promise, I’d hesitate to send him to one of the big companies. I’m with one now to learn what it’s like. As an experienced arborist, it’s not been too bad, but for an up-and-coming climber, the pace of opportunity to grow his skill set will be painfully slow.
As was mentioned before, find a good mom-n-pop shop. One in Blacksburg, VA is great for turning hungry people into skilled crew leaders with advanced climbing and rigging experience in two to three years. I’d be happy to connect you, if interested. In NC, Heartwood Asheville will test a climber. They are an insanely skilled team that will push you. It’s grow or go. Check with
@rope-a-dope to see if they have room.