I take mine out just around my neck when I'm getting the mail or watering the plants, and only on very warm humid (50%ish days). I did let him down once in the garden for pictures with the spring blooms, but was so afraid of parasites or ants that I didn't let his stay on the ground and didn't actually take any pics - even wiped him down with a damp towel afterwords. He seems to tolerate it well, maybe gets some enrichment from the new smells. I keep an eye on his respiration rate to make sure he is not becoming stressed; but it is certainly not a common occurrence.

He has a "play" area in the house for exercise. Mainly a large empty walk-in closet that I have snake proofed, added rocks and branches, different textured surfaces, hides, and a large pan of water. I'll sit in there with him for 10-40 min while he explores then when he starts to seek a hide he goes back in his cage. It seems to help his restlessness and he has great muscle tone. This is still only done a few times a month, more often now that the house ambient temp and humidity are actually within his safe range.

I also would NEVER recommend letting them roam unless you are watching every move they make, I'm sure younger snakes can get a move on if they want and escape if you stop paying attention for even a min.