That sounds excellent, and he would find a lot of people willing to help and/or teach him how to meld magic and tech in the context of the world, especially with higher-level tech/electronics. People would definitely be interested in his designs.

I'd say to let me know if he gets to the point where he might destroy parts of the city, or if there's anything that might compromise the game mechanics (for example, world hopping, time control, etc.). Aside from that, if there's anything you'd like to see released into the wild that he's created and you're uncertain or would like to get it out there, just let me know and I'll talk it through with you as a player plot!