I have not been taking measurements. I have gained size but I have also been lax with diet so have gained substantial fat in the process. So definitely a calorie surplus. That said, when I first started the programme I was still doing a bit of regular 48-hour fasting (on non-training days) which didn’t negatively impact on my lifts.
In terms of tweaks, yes. My lower back precludes me from any sort of deadlift, bent over row and most squats. I rely on a belt squat for the so-called ‘widow maker’. Although I appreciate this is in no way as intense as a regular back squat. I do several chest-supported row variations for back thickness.
Other tweaks I learned from other DC sources include upping the reps for older lifters and/or when using DBs. This has been a revelation for exercises like chest presses, where getting heavy DBs into position is a challenge. What I do is aim for a load that gets me around 25 total reps (x1 main set then x2 rest pause sets). Once I hit 25, I up the load next time.
I have also abandoned DC calf training. I tried this for weeks but felt nothing. I currently do a version I heard about here from Drew Baye: 1 set to failure using a 10/10 cadence with a 3s stretch at the bottom and 3s squeeze at the top.
I also have found using bands for the loaded stretching aspect much more effective than weights for certain body parts, namely, pec stretch for chest, or handcuff stretch for delts.
I personally believe the workout rotation, where you perform the same workout every 2 weeks, and loaded stretching, are the two main drivers of progression. For example, I have noted that, unlike other programmes I’ve done, with DC training I invariably get light but sustained DOMS every workout.