My 2:1 analog MUX PCBs arrived, and got them all assembled :)  Read the logs below for more details - I'm using these to make the digital pots more precise, and give me full speed :)

I'm a fan of TSSOPs...pretty easy to solder, and even easier to fix mistakes or shorts.  0.65mm pitch is small, but still doable.  These boards came out pretty nice...but how small are they really?

Here is my finger for reference...pretty small still!  Not worried about fitting everything inside the wheelchair tiller :P

Now, to test the functionality with a simple LED on/off.  I cleaned up the Arduino built-in debounce code (it's a bit iffy, but works) and made a toggle function:

Success! The MUXs work exactly as intended on first iteration design :)

[to be continued...]