5-star level awesome product. Hands down the most versatile volume pedal out there, and also the smoothest operator! When you take the built-like-a-tank aluminum chassis of the VP Jr and put these seriously engineered electronics in there, you get the best volume pedal out there in my humble opinion.
I bought the DIY kit with all the options and put it all together in Jan 2021. I get by with a soldering iron but I'm no expert. While I guess it was not a "beginner" level project, it was certainly within reach of most people who have basic soldering skills. The instructions are very thorough and leave nothing to the imagination. I had a blast putting it together.
Even if you don't have an Ernie Ball VP Jr laying around - go and find a used one just to do this project! Other volume pedals with similar functionality are 3 times the price,