On my next workout, I gave wall pushups a try instead of doing a usual pushup routine to give my shoulder some rest. In order to not feel cheated, I used this opportunity to practice muscle irradiation by actively trying to isometrically twist the wall apart as I performed my lowly wall pushups for 50 repetition sets.
I started playing around with irradiation, twisting apart for a repetition, and then together for the next repetition, one after the other for 50 slow repetitions. Over time, I felt a burn in my upper back, right around the rotator cuff and felt some painless clicking in my elbows, wrists, and shoulders. When I finally concluded my set, I tentatively raised my left arm overhead and felt no pain!
The tension practice had made the impingement "smaller," for lack of a better term. My shoulder still cracked, but it cracked painlessly for about 20 minutes following the set.
This might be useful info for any comrades out there with shoulder impingement pain. It definitely helped my shoulders better than any of the shoulder isolation work I tried.