focus jumps to random row after pressing enter while using cellNav with edit enabled

[pruttned]

Hi,
in grid with edit and cellNav enabled randomly happens, that after pressing enter key in cell, the focus doesn't jump to next row, but instead it skips few rows and sometimes it goes all the way to top. It happens in longer grids after some scrolling.

Video of the issue:
https://imgur.com/ntnCdPv
Plunker:
http://plnkr.co/edit/Q8CW68OWovbt7NDFbAJs?p=preview

Thanks for any help.

[pruttned]

From my debugging it seems that the erratic behavior is due to track by $index in ui-grid/uiGridViewport.
In the uiGridEditor directive is scope.row changed during execution of uiGridEditConstants.events.BEGIN_CELL_EDIT

module.directive('uiGridEditor',
    ['gridUtil', 'uiGridConstants', 'uiGridEditConstants','$timeout', 'uiGridEditService',
      function (gridUtil, uiGridConstants, uiGridEditConstants, $timeout, uiGridEditService) {
...
 post: function ($scope, $elm, $attrs, controllers) {
  ...
                // set focus at start of edit
                $scope.$on(uiGridEditConstants.events.BEGIN_CELL_EDIT, function () { 
<<<<<<<< Here it is correct >>>>>>>>
                  // must be in a timeout since it requires a new digest cycle
                  $timeout(function () { 
<<<<<<< Here it is invalid because queueGridRefresh was called and that shifted rows in setRenderedRows and therefore changed scope of the currently selected row >>>>>>
...

If I remove track by $index, then it seems that it works, but it is most probably going to kill performance.
Is there another option?
Thx