In FE8, if Ross, Amelia, and/or Ewan are at level 10 and still in their starting trainee classes when the battle preparation menu is called, they’ll have a few lines of dialogue, and the game will automatically send you to the promotion menu for them for free without requiring an item.
I’d infer that it’d be easy enough to simply change the dialogue they have and write one’s hack-original trainee characters over their slots, but what if I want to have a fourth trainee-type unit with their own free prep menu promotion upon reaching level 10? How would one go about adding that sort of thing? My current assumption is that it’s all hardcoded stuff, which means having more than three characters promote that way in a given FE8 hack might get rather complicated.
Has anybody played around with or done any research into this? What, if anything, is currently known about it?