I’m big on giving people stuff they enjoy. I had the advantage of doing all my teaching during the iPod revolution, so pretty much every kid ages 9 - 18 had a slew of favorite tunes. What’s he into?
If you can find stuff he likes, you could think of parts that lend themselves to single escape picking. Or you may have to be imaginative and tweak one of his “likes” so that it’s got single escape capabilities. Just off the top of my head, say for instance he likes the Crazy Train intro riff. That still sounds cool if all the notes are double picked, and then you’ve got a simple-ish USX etude.
Or, maybe AC/DC’s “Thunderstruck”. Again, all double picked will reduced the left hand speed issue and he can concentrate on the picking. That might be better than the Crazy Train suggestion because it all stays on one string so it might be a great opportunity to see if he gravitates toward USX vs DSX.
Again, all moot if he hates all rock music and only likes Blues or something lol! I might have better suggestions beyond the hypotheticals I listed if you can give examples of things he likes.