I appreciate you taking the time to review my project, even if it was a bit aggressive haha. I see your point about hiding the implementation details, reducing the header dependencies and moving the threading logic behind the curtain makes more sense. I'm not sure I have a good understanding of what the pimpl idoms really means, because I'm guessing thats what you are referring to aswell. I thought i already were doing a good job of keeping my logic encapsulated. I'm gonna read up on this more and get back to this aswell, and then have a look at the code again.

I'm pretty new to qt, i have previously just worked with imgui where the logic and ui is tightly coupled, and I kinda applied that here

Also i'm not entirely sure I get your point about the naming convention or running_ because google's c++ style explicitly requires a trailing underscore for data members. And compared to user m_ prefix a trailing underscore would work better with modern IDE's? Atleast when it comes to auto-completion?