I have an avail and an xcurve minimalist set up. For longer hunts I'll strap the avail to the xcurve, takes less than a few minutes to get from the minimalist set up to having the avail on the frame if you know what you're doing.
I liked the xcurve more than the krux after trying both but I suggest you do the same since the xcurve doesn't seem to fit everyone the same way. Xcurve can be used as a stand alone hauler in minimalist mode (dry bag, meat shelf).