qvacua
'set columns' and 'set lines' don't change VimR window
This might be related to #932.
In MacVim, I can use set columns=N and set lines=N to change the dimensions of the vim window. I use these so that I can script changes in the window size. This is very useful for me.
Those two command partially work in VimR, but they only move the status bar, and then it's in the wrong place in relation to the window. These commands don't change the shape of the VimR window. (Resizing with the mouse causes the status bar to move to its correct location, but the point is to avoid using the mouse for a resizing operation that I do all the time.)
If there are some other commands that will accomplish the same thing, I can use those. I don't care whether it works exactly the way that Vim does.
Another interface that could be used is winsize from the Nvim GUI help file (":help GUI"). I think this is just text carried over from Vim. It might not be implemented in Neovim. winpos would be nice to have as well. (I use these in shell scripts that I use to start MacVim in different configurations for different kind of work.)