Am I reading this right - 1 (one!) day for ALL theory and confined sessions?
Nearly every dive shop as well as most charter boats and independent shore instructors have to offer the 3-day cert; the market demands it. It's actually easier to do 3-day certs at many resorts, because the pool and dive site are within walking distance.
Proscriptive is the term I think; if the students have the correct answers on the knowledge review, move on. The students take turns reading each question and their answer. The first three chapters are pretty easy if you actually read the book; a 10 year old can do it.
The only real teaching required for most semi-intelligent people is how to do the tables. Some never get it, but you can miss every tables question on the exam and still have a passing score. You must review every missed answer but computers are the best advice for many divers. 3-6 students; KR's reviewed, quizzes taken, exam probably passed, all in 4-4.5 hours.
Gear up, load up, eat lunch while driving to the pool or confined water, hope to have skills done by 5 so clean up done by 6.
The other 2 days are easier;
Gear up, load up, drive to dive site, dive, eat lunch during SI, , dive, return to shop, clean gear. Retakes of exam could happen end of second day, PIC processing end of third day. 10 hours first day followed by two ~7 hour days; 24 hour course, we might be lucky if that's close to the industry standard (most probably aren't that long).