Just a small wish. A loudness meter at the top of renoise, where the master level meter is, next to the clipping indicator, would be great. So we can see the current loudness of the track all the time. And it should be configurable with different algorithms Perceived/RMS loudness calculation and different calculation window.
or you could get a vst and not wait till renoise 4.0 and forget about wanting it natively much much sooner 
I currently use a vst for it. But i really hate floating windows. The all in one window concept in renoise is perfect and the master level meter is soo big 
There is enough space for something useful like a loudness meter.
find a very very thin loudness meter then disable the VU metre and put the floating window in its place (right-click-disable)
I didn’t even know a loudness meter existed, sounds cool though. 