I haven’t tried galantamine, but didn’t find the drugless techniques all the same. The standard advice of keeping a dream diary and psyching yourself to have a lucid dream and to do reality checks never worked at all for me. Wake-back-to-bed on the other hand got me dozens of lucid dreams and often worked the first time I tried it after a break. It’s also annoying to do because it involves messing with your sleep cycle and waking yourself up in the early morning, and it seems to always stop working if I try to do it multiple nights in a row.
Agree with the other parts though, the lucid dreams are generally pretty short, kind of samey. Maybe it takes a longer dream for the narrative to get properly weird, and the WBTB lucids are more often short dreams that start out of nowhere than becoming lucid midway through an involve dream. They’re also too sporadic to get any sort of ongoing active imagination practice going since I don’t have any routine of trying to WBTB once every week or something. There’s Robert Waggoner’s lucid dreaming book that talks more about possible ongoing psychological development you could make happen with repeated lucid dreams, as opposed to just the “hey, lucid dreams are a thing” books, but I guess a regular routine and some kind of intentful approach would help a lot here.
One thing I’ve been thinking is that the stories about shamanic journeys sound a whole lot like lucid dreaming, so maybe you could take a page from there. Try to travel to the underworld or overworld, meet some spirit entities, ask them what’s up and maybe have a nice chat about large integer factorization.
Lewis Dartnell’s The Knowledge—How to Rebuild Our World From Scratch is a sort of grand tour for technological underpinnings of industrial civilization and how you might bootstrap them. Might be a bit dry, but it’s popular writing and if the kid’s already reading encyclopedias it should fit right in. Lots of concrete details about specific technologies.
Might go for a left field option and see what he makes of Euclid’s Elements.