I'll throw my hat it. Caution: I'm not even a nursing instructor, so I'm pretty blind flying here.
BSN model, based on a liberal arts and sciences curriculum in the first two years which creates an individual educated on a broad base of knowledge from the sciences and the liberal arts. Last two years are nursing curriculum with curriculum continuing into the summer between the junior and senior year. The student must have the "CNA" credential coming into the junior year.
It is a long time since my diploma program, but I think that by the time a student is a senior a semester from graduation, they should be doing 2 full length (which I will define as 8 hours) shifts per week. Unfortunately, I do not think students should routinely do 12's since the main goal is still to educate a student, not turn them into extra labor. A senior practicum should include 12 hours shifts if that's what that clinical site is doing, so the student gets the ebb and flow feeling of the clinical day. Beginning students have so much information to learn that it might be challening to give them 2 full 8's at first. A person experienced in nursing curricula could better speak to that.
People on the board who have taught in nursing schools
will tell you that they strive to balance didactic information with clinical and meet NLN criteria.
Understand that the mass of didactic info that a safe practitioner must have in their head has to be taught somehow, somewhere. This mass is much greater than when I was a student in 76 thru 78. Remember from whence we came, the diploma programs which in their very earliest days were little more than cheap labor forces for hospitals; their "education" came secondary. (In the very olden days, they often simply staffed night shift.) Don't mistake how difficult it is to create this balance of didactic and practical experience, both critical parts of the whole.
So whaddya think?