I just want to update you on my progress with this issue. I tried all sorts of things to stop the popping and was about to pull it out of my multi effect build when it occurred to me to try one last thing. I had wired the board in at the very start of the chain to make use of the input buffer although that isn’t something that my build really needed. I moved the input to another stage and the pop is nearly gone. That leads me to believe that there is a small voltage potential difference at different points in my circuits. That’s usually not a big issue but was exaggerated by the trail in the delay signals. Now it’s working pretty well.
Thanks for your support on this. Case closed! 🙂