It’s not a very good program for max reps. But I think it’s more designed just like all of the marine training programs are designed - to push your limits. Most of the people who come there don’t know their physical and mental limits and don’t know how to tap into their energy reserves.
These grueling drills will let you in on two things: discovering your limits and seeing whether you can take it or not. So it’s not just about how many pull-ups you can do, it’s about testing character and inner strength.
I agree with that.
For max reps in a single set I’d suggest 3 to 10 sets per day every day, spread throughout the day with at least 45 minutes in between each set. Day 1 go to 80 to 100% intensity. Day 2 go about 50%. Day 3 repeat day 1, etc. Adjust intensity and volume as you see fit.