I found Projeqtor a few weeks ago by accident, and I am still in awe how versatile and smart it is. I think I have tested most of the available project management code on Linux, and while your UI is not always the best, the code, feature-wise, is not even in the same universe as the others. I still try to get to know the various logic in Projeqtor, and I  apologise in advance for my questions yet to come.