What exactly - from an end user perspective - do you worry about? Performance? I already showed in my benchmarks that my block editor is faster than all block editors on the market - even more than those that uses native frameworks.
And as I wrote to another commenter: "if you avoid writing Javascript code in your QML components, than most of your executable will end up being compiled C++ code. If you do write Javascript code in your QML components, than it could also be compiled to C++ code using the QML script compiler[1[2]."
BTW, I agree that there's not enough good documentation about communicating and connecting C++ and QML code. I hope I could write some tutorials for that in the future as I struggled with that when first delving into this.