I tried another board using a fresh parts because the shift registers on the first one were too hard to desolder (the solder kept flowing onto the pads on the other side before I could suck it up). It was reproducing the same quirks as the first one. It probably is a design problem that I’m not seeing. I’ll try to figure it out but I’m taking my focus off of them now. I’m still extremely happy that the Attiny85 boards work. That was the main design anyway. The shift register design was just added on because I had the space.
I will be working on the minisite for the Attiny85 board. I don’t mind if you visit it while it’s under construction. There are some other exciting things coming up as well. Stay tuned!