Wow thanks for reading! And thanks for your great work on CARMA. I was very excited when I found out about it and have been using it in a number of projects.
I think the defaults are OK as is - its more of a heads up that users should be aware of.
I didn't think about the conversion actually - perhaps using double in C++ will eliminate some of the overhead.
And absolutely, please feel free to share / link / include these examples. The complete code is easier to read on GitHub.