I suggest we have the something like guides in the Pattern Matrix; like in Photoshop (The blue lines in the picture below):
What I really want is the ability to draw a square in the PM. Sometimes I get lost trying to figure out which part of the song I’m currently working on. Renoise Guides would allow the user to highlight areas in the PM so that they can keep their focus.
Yes, this my main gripe with current Renoise as well, it isn’t immediately clear where you’re at all the time, the selection highlighting in the matrix especially can use some work.
Made this thread a while ago: It Aint Where You From, It'S Where You At!
While grapically lollable, I wouldn’t mind some hard borders.
That border could actually be useful - and it should be scriptable 
tetris? 