at least Gifted sorta implies just a really smart person by real world standards, no? Allan can apparently create rocket boots which are already a
nearly impossible feat in real life especially by yourself. Rocket boots that can break escape velocity and make it to the moon in a reasonable amount of time is borderline Extraordinary Genius.
Granted as far as I can tell theres no specifics on how long it took but even if it took a full day the boots would fly at 16016.6666667 km/h or Hypersonic
So either way Allan somehow engineered a way to keep enough fuel in those tiny boots for the full two way trip which would be at
minimum hundreds of thousands of gallons of fuel which take entire teams of highly intelligent scientists a long time to calculate but Allan could do that by himself.
So imo I think Allan should be "at least Genius"