Don't discount the LO206 class. They tend to be large classes, competitive and fun; particularly for people new to the sport and of a certain age.
The sizes of the class tend to negate the "boredom" aspect.
I ran Karts back in the 70's and our son ran TAG 2-stroke for years with me as the chief mechanic and sponsor.
Plus, I would break engines in for fun. We also had a LO206 and the level of maintenance and cost are orders of magnitude less than most 2 strokes.
There is a lot to learn about making a kart handle (everything is backwards from a formula car) and more seat time and less working on it time can be a big benefit.
The IAME 100cc is a nice engine and a bit easier to tune than a Yamaha but there is still an art to the process. You can always sell an LO206 and my suggestion would be to start there and see where it goes. I know several people that started in 2 stroke classes that moved to LO206 and are spending far less money and having far more fun.
Just my 2 cents worth. Bottom line is that it is a blast!
Our son in the 199 kart.