Thanks for the feedback. I'll try reducing the ROM a bit to see how that feels. I have read TNW, but, as you point out, I am still learning to apply the techniques.
I think you're right that I should increase the reps in reserve. I'm not really fond of doing sets of less than 3, so I'll probably switch to a higher elevation that will allow me to do sets of 4-6 with more RIR. Come to think of it, I think this is probably the main issue. The times when I've been most sore were when I've really pushed hard, so just pulling back seems likely to fix the problem.
Re GTG: My current program has me doing a single "circuit" of 3 exercises 3-5+ times across the day, but it's not "circuit training" since I wait for my heart rate to return to normal between sets. So I'm waiting at least an hour between repeating an exercise. I want some hypertrophy/body recomp, so I'm aiming for 1-3 RIR on all sets, and alternating movements daily in an A/B split (push/pull/squat on M/W/F and front/side/back core Tu/Th). This resembles a GTG protocol, but the deviations are intentional.
Of course, the rationale behind that intent is certainly up for debate. I am making progress.