have several qualified pilots amongst our staff.
Would these qualified pilots be willing to act as instructors /examiners for your scouts?
The reason I ask is because one of our own members who is an instuctor has set up a 'virtual' PPL syllabus for members here to work their way through (
SEE HERE). Maybe you could set up something like that?, The students/scouts can do their training (at home if possible) & then perform an FS checkride on your trainer whilst being evaluated by your qualified pilots. The result being a 'Virtual PPL' if all the criteria are passed.

TSC.
To not focus so much on sim flying, as in demonstrating piloting skills in front of a monitor (because on some levels it takes more of an attention span than real flying.. a bit challenging for a 12 year-old)...
The lessons mentioned here (yeah, they're mine) aim to get the piloting frame of mind working. You know.. all the mental gymnastics involved in flight planning.
I think a well documented flight plan, that includes everything from learning to interpret aviation weather data .. to the mathematics involved in course plotting and wind compensations, would be excellent criteria for a merit badge.
But of course I'm biased, and think every young person should be learning all about every aspect of aviation.
If you read through my lessons, and have any questions about adapting them to meet your needs.. feel free to ask