I donβt really think the rank itself needs a change because, as it stands, what any given Shoi Kohosei does changes depending on their plot and commissioning source.
SAAMMS cadets, for example, will always have a destination MOS by graduation. Theyβll have already chosen Uchuugun or Rikugun service preference and attended at least one βsummer cruiseβ aboard an active duty ship. Some are sciences specialized. Beyond that, they might not be locked in, but will generally have trained towards a specific skill set by graduation. They rarely appear on ships/plots (though mine is detailing some right now).
Miyamae Officer School students get basic officer training and then are shipped off to attend specific occupational training as freshly promoted kohosei. These ones are kohosei during their assigned/selected MOS training by design. They donβt really appear on ships/plots prior to MOS selection.
Where this all really matters is for Kyoto War College remote learning kohosei (notably the only remote learning officer path, others require physical attendance). In my experience theyβve never really had an MOS selected until promotion to full Shoi. When I played Aiko, for example, she just kind of floated around as a kohosei and did whatever her captains asked of her as part of the learning experience, and only selected an MOS upon promotion to Shoi. They should generally be classified as whatever MOS they already earned as enlisted (since the vast majority of KWC kohosei are mustangs leveling up in the field) or as basic soldiers with no specialization for the rare cadets who do this.
So it sort of already works like you want it to both in fact and in RP precedent.