@life4h1m
The question is has anyone tried this with bodyweight workout? Could it work? If I remember correctly, K Bogues argued in one of his clips that one hard set could be enough, but I think he suggests doing it on a daily basis.
A set with 1 or 2 reps in reserve is a hard set! The irony is that the people who say, "Leaving one repetition in the tank isn't training hard." probably don't train hard. If there is an exercise that you can do 10 reps, and you do 10, the 9th repetition should not feel easy!
There is a genius with Mentzer's programming. Most people who are not resistance trained underestimate their reps in reserve. So if they follow programs that say to leave two reps in the tank, they often leave four or five repetitions, meaning no gains. So Mentzer's program will be hugely better than the effort most people put in. Mentzer's program is also good for people who don't rest enough.
When you realize that 90% of the people working out are not training hard or recovering enough, then Mentzer's program is better than what most people are doing.
However, higher volume leads to more muscle growth.
Your volume should be as high as it can without sacrificing intensity, movement quality, and recovery. For most people, that is higher than what Mentzer prescribes. Volume is a factor in muscle growth and doing over 10 sets leads to more muscle growth for most people.
https://pubmed.ncbi.nlm.nih.gov/27433992/ (The people in these studies had researchers prodding them to do more reps. They were training to failure.)
Now in terms of calisthenics, having such a small rep range could limit you if you don't have a loadable weight vest. I would expand the rep range to at least 5 to 15. You can't really progress on certain exercises with such a small rep range. Progressing calisthenics exercises can require more skill, joint stress, and load. (Pushups -> archer pushups is not like adding five pounds to a bench press).
I am someone who can go very hard. If I train like HIT recommends, I would be injured and sore all the time, the opposite of my fitness goals. Most of the HIT advocates use a lot of machines. While this is fine for bodybuilding, you are removing a lot of the stabilizer muscles, which will promote overall health and real world strength. Andrew Huberman, a user of HIT, has no hinge movements in his main fitness program. The hinge movement pattern is the most beneficial pattern for athletics. No "functional" program should omit it. That's cutting off your nose to spite your face.
HIT without machines is a recipe for injury.