Apparently I've been playing more that I used to, and I have the calluses in my fretting hand to prove it. Yes, I've been playing a lot of sliding vibrato stuff (+ - 1/2 step). NO BLISTERS!
I've doing the nightly treatment with https://www.amazon.com/Gena-Healthy-Hoof-Cream-Ounce/dp/B0006Q00ZI...