I find this stuff pretty fascinating. I would credit Dan Moore for being the first to really get into exploring some of these issues based on hypertrophy research, i.e. abandoning conventional set/rep approaches in favor of something truly more hypertrophy-specific.
At Dan's board, there was a conversation between a few of the regulars about this subject, which I still sort of remember. I think it was Ron Sowers (NWLifter, awesome/bright guy) who was the first to say something to the effect of "what if we used max-stim and turned it on its head, using it to maximize the density of training?" Or something to that effect.
I think a few different versions of this idea arose, with Blade clearly doing the most legwork. I have actually experimented with it myself, and came up with a "dumber" version that I actually found easier to use, that went something like this.
If we're relating this to RPE, the idea is to stop any particular set or mini-set at maybe an ~8 or 9, tops. Meaning we always have at least one rep in the tank. In practice, this means terminating a set when one rep is noticeably slower than the previous rep, or some spontaneous change in form has happened that we can't control (more an issue on squats and deads).
And with that in mind, I basically used the rest periods in DC training and would do something like this:
"Activation" set with a ~10-12 RM. This might be 7-10 reps or thereabouts.
~12-15 deep breaths, or ~30-45 seconds. Do the same as above - you might get ~4-5 reps.
~12-15 more deep breaths, repeat until you get to your total intended rep count. A good rule of thumb I found was ~2 x (RM). E.g. 20 total reps with a 10 rep max, 25 total reps with a 12 rep max, 15 total reps with an 8 rep max. That sort of thing.
I liked longer rests like this vs. shorter rests due to the fact that it can become really difficult to predict drops in performance with really short rests, at least in my experience.
You'll also notice that a roundabout way of knowing whether you're at "full" activation is if all your subsequent sets fall within that ~5 rep range or less range, which in my experimentation they always did (and I usually only got 4-5 reps on the first mini-set, and more like 2-3 reps on sets after that).
Now, I'm not trying to compete with Blade's myoreps here, but for a poor man's version of the basic concept (i.e. maximizing training density with a medium-heavy weight while proactively avoiding failure at every step of the process), I think it's a good way to know what this "feels" like, for anyone interested.
I'll give an example of what this looks like with, say, chins...
Say you're able to do 10 strict chins with bodyweight. Okay, cool. We'll double that 10 RM to arrive at a rep goal of ~20 reps.
So, we start off, and perform our chins strictly until we get to ~7 or 8 reps, at which point we notice a sudden change in rep speed, i.e. things start to really get grindy. This is about an ~8 on the RPE scale.
We take 12 deep breaths (maybe 30 seconds rest), then continue. Now we get another 5 reps, at which point we notice another sudden drop in rep speed (RPE ~8-9). 8 + 5 = 13. So far, so good.
12 more deep breaths, and this time we get 3 reps using the same criteria.
Another 12, another 3. 8 + 5 + 3 + 3 = 19. We probably don't really need another 12 deep breaths to get the last rep, so you rest as long as you need to know you'll get one more quality rep (maybe 15 seconds), then you're done.