Good job, User. Your memo certainly rebuffs the claim that "secured" means "locked". I'm guessing that the next round will entail using your examples to show what "secured in a container or compartment" means.
§ 18.2-308. Personal protection; carrying concealed weapons; when lawful to carry.
10. Any person who may lawfully possess a firearm and is carrying a handgun while in a personal, private motor vehicle or vessel and such handgun is secured in a container or compartment in the vehicle or vessel.
For example, if I remove my holstered HG from my belt and place it in the glove compartment as is, the entire package can still move around, and would not be "secured" because there is no restraining device attached to both the holster and the container which would restrict movement within the glove compartment, even though the gun cannot move within the holster. Now if I had a holster fastened inside the glove compartment and inserted the HG into it, then the gun would be "secured in a container or compartment in the vehicle". As a practical matter, the glove compartment in my wife's car is fairly full, leaving little room for my holstered HG to move around, so in this case, I'd claim it's secured. Also, when the vehicle is parked, there's little possibility of motion.
Now, if I put the holstered HG into an empty briefcase, or I put the HG into a holster attached inside the briefcase, then leave the briefcase on the seat...