A lot of heavy powerlifting programs have a few minutes rest between sets, which while not great for longform, does allow for a minute or two reading once your heartrate comes down a tad
It's supposed to be active rest, and even then, if your heart-rate is low enough to where you can comfortably read anything, you're definitely not working out with enough intensity to matter, let alone call it power-lifting. You should be dreading the next set, basically, and get right back on it before your heartrate comes down.
I am interested in the source of your expertise
Plenty of reputable programs call for up to 8 minutes of rest if you need it. Powerlifting is not cardio; the idea is to lift as much as possible even if that means letting your heart rate drop to RHR between sets.