No way to obtain `fort_vehicle` from a `vehicle_spawner_device` at a later point of time

Hi, I am exactly your use case - a beginner trying to workaround this issue to get the fort_vehicle using the currently available methods. I do not understand the closure method outlined by @latunda in the example they linked. Would either of you be able to weigh in on the proper method of doing this (currently) on my other post? Thanks!