Furthermore, there might be a matter of how many classes outside your specialty you might be interested in taking. Are you looking to be involved in R&D, ONI, or other sub-branches that might require additional training?
This would allow for a great deal of variety, and people’s personal storylines could match their needs.
Until we hear otherwise, I might posit: as long as a piece of rope.
How long you are there, depends on how long you NEED to be there. Different people might graduate at different rates, depending on competency, skills coming in, etc.
Actually, encrusting objects with precious materials is fairly common among many skaraan crews. It is a way to increase it demonstrate one’s status. At least that’s how they tell it back home.