I have found the spokes actually loosen while
riding in my Magic Pie. (It has been trued once.)
I have never had a double walled rim before, I think
that the inner tube has always pressed the spoke
caps and held them on other rims.
I just re-trued my rim after one cap actually came off
and fell into the rim.
I am going to put lock-tight on the caps after I ride and
re-true it once more.